Customer Reviews


6,174 Reviews
5 star:
 (4,530)
4 star:
 (955)
3 star:
 (209)
2 star:
 (133)
1 star:
 (347)
 
 
 
 
 
Average Customer Review
Share your thoughts with other customers
Create your own review
 
 

The most helpful favorable review
The most helpful critical review


2,102 of 2,146 people found the following review helpful
4.0 out of 5 stars Does the job well/tip for Comcast users
Out of nowhere, I was having excruciatingly slow internet speed on Comcast. The Comcast tech advised that my Motorola SB 4100 was at the "end of life" and that I should upgrade. Skeptical, I purchased this modem which is a DOCSIS 3.0 (and backwards compatible) modem. It worked. I went from a 2mbps download speed to over 17mbps. What a difference. There was one...
Published on September 29, 2011 by T. Hyatt

versus
269 of 298 people found the following review helpful
3.0 out of 5 stars Potential issue you may face with Comcast
I had bought this modem about a month back for my connection with Comcast based on all the stellar reviews it has received. However, the modem just didn't stay connected on my line and kept rebooting every hour or two, and sometimes took a good 15 minutes to reestablish a connection. Comcast promptly blamed the modem for my connection problems, but I insisted they have a...
Published on August 7, 2012 by Ezhil


‹ Previous | 1 2618 | Next ›
Most Helpful First | Newest First

2,102 of 2,146 people found the following review helpful
4.0 out of 5 stars Does the job well/tip for Comcast users, September 29, 2011
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
Out of nowhere, I was having excruciatingly slow internet speed on Comcast. The Comcast tech advised that my Motorola SB 4100 was at the "end of life" and that I should upgrade. Skeptical, I purchased this modem which is a DOCSIS 3.0 (and backwards compatible) modem. It worked. I went from a 2mbps download speed to over 17mbps. What a difference. There was one installation glitch that you need to be aware of. When you hook up the modem (connect the coax cable, connect the ethernet cable, and plug it in, that's it), and then try to get online, it will direct you to a Comcast self-activation screen (no other site is available). After entering my account number and phone number and hitting the "next" button, I got a blank screen, and nothing happens. So I called Comcast and they said that usually happens if you are doing an upgrade; it mostly works only for a new service connection. However, it is a simple matter to give the tech your MAC address and the serial number. After about 5 minutes, while he stayed on the line, it came alive, no problem. BUT, here's the thing: the serial number they need is the CUSTOMER serial number. This is only found on the bottom of the Motorola box the modem came in. This is different from the "S/N" serial number that is on the label that is on the instruction sheet and on the bottom of the modem itself. The customer S/N has letters in it; the regular S/N has only numbers in it and is too long. My first Comcast tech didn't know that and it took a day to sort it out. Other than that, it works well with my iMac and Apple Airport Extreme Base wireless router. Enjoy
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


1,420 of 1,483 people found the following review helpful
4.0 out of 5 stars Modem NOT defective - Comcast conspiracy?, February 4, 2012
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
I felt compelled to write this to help those who will encounter the problems I faced (and mentioned here). I'm one of the many people who wanted to avoid renting a modem from Comcast and bought this modem based on the stellar reviews, only to find that on the day of installation/activation that it "didn't work". Didn't work meant experiencing the same symptoms that's been mentioned here several times - "modem connects but then resets/power cycles/disconnects itself within a few minutes." This happened to me on the day I activated my Comcast internet. The technician spent 1.5 hours trying to figure it out and ended up loaning me a Comcast modem (Motorola SB5120 DOCSIS2), which came up almost instantly and activated just as fast (go figure). He suggested I return this modem as it was defective, in his opinion. I didn't like this since the probability of this was very small. But I saw what I saw and could not get past the first page of Comcast self activation screen with this modem. Before the web page for self activation could proceed, after typing my account info and phone number, the modem would conveniently lose connection. At one point I did get to the next screen where it was scanning for devices, but the modem cut out thereby hanging the process. The modem was packed up in the box for return to Amazon when I couldn't shake how much this bothered me and by my bad luck. So I came back here and read pretty much every review. What I found was there's several people who experienced the EXACT same symptoms while trying several of the same modem. There were two reviews that stood out. One was from a person who mentioned the Comcast technician moaned when he saw it was this modem, indicating that the technician was aware of difficulties using this modem. The person mentioned that after 70 minutes of trying to get the modem to connect the technician advised him to leave the modem powered on and hooked up for awhile and to try activating later. The person did this and was successful in activating the modem. The other review was from a person who was admirably persistent. His review talks of several attempts to connect and refusal to accept that the modem was defective. He ended up leaving the modem power on and connected overnight so the modem could "download firmware". The next day he was able to activate after two attempts with Comcast self activation process. Lastly, I noticed for me that if I left the modem power on and connected but make no attempt to activate it via Comcast web site, the modem retains connection (via indicator lights) for prolonged periods of time. It only seems to lose connection when I try to activate. Based on this I felt something was broken with Comcast activation process specifically for this modem or perhaps Comcast was intentionally making it difficult to activate this modem to convince customers to rent a "reliable" modem from them. To be honest, it almost worked for me. After sitting there watching the technician agonize trying to get the modem to work, I was tempted to rent the modem and move on with life. So as one last hail Mary attempt, this is what I did:
1. Took the modem back out of the box and left the Motorola SB6121 power on and connected to cable outlet overnight just to entertain the possibility that some firmware or info needed to be downloaded to the modem and that for some reason it took a long time to do so.
2. The next morning I tried Comcast's self activation process.
3. Every time Win7's network icon in the lower right corner of my screen indicated that a internet connection was established (vs. exclamation mark) I immediately opened a IE windows and started the activation process with my account and phone #. The modem still lost connection when I did this but I kept on trying.
4. It took me about 4 tries to SUCCEED. Each time I tried, I started back on the account and phone # page. But each time it got further and further in the activation process.

Attempt #1: Account/phone # screen -> Retrieving Device Information -> Modem lost connection.
Attempt #2: Account/phone # screen -> Retrieving Device Information -> List of devices detected (screen showed my MOTR SB6121 modem and a DTV box both shown as "inactive" -> Modem lost connection. (A thing to note here is that Comcast's activation system could specifically identify this modem. This meant it was in their system and their system was able to communicate with it)
Attempt #3: Account/phone # screen -> Retrieving Device Information -> Listing devices detected -> Clicked "Rescan" device (modem)-> Hit "Next" to activate then got to screen where it said "Activating Device - This may take 10 minutes" -> Modem lost connection
Attempt #4: This isn't a real attempt because all I did is leave the web browser in the previous "Activating Device" screen and waited for the modem to re-establish connection again. I stepped away for a few minutes and when I came back I got a screen that stated "Device Activate" (and some other instructions that didn't matter) Hallelujah! Also note, NO phone calls had to be made to Comcast to activate this modem.

At this point, this modem which was losing connection all the time before, now had a seemingly rock solid connection!!! I'm using the connection now with this modem as I type this. I've did some basic testing, streamed video, surf the net,etc. NO LOSS OF CONNECTION! I did a speed test and I'm getting 25Mbps down and 3.8Mbps up.

Based on my experience so far, it is in my opinion that this modem works and is as good as what the majority of the reviewers here have stated. The problem lies in Comcast's self activation process which is suspicious. What doesn't make sense to me is the fact that modem can hold a solid connection if you didn't attempt to activate and after it's successfully activated. It was only when I tried to go through the self activate process that I saw problems. I can't say much about whether step #1 helped but it can't hurt to try. I mentioned it only to inform people of what exactly I did.

I truly hope this helps people. Amazon is top notch. This modem is now doing what it's suppose to do with no issues. I'll come back and update this review in about a month to report if it still holds true. I think it will but we'll see. And lastly, thanks for the people who shared their experiences here. If it weren't for them I would have returned the modem back to Amazon and go through the hassle of finding another modem or giving in and renting one from Comcast. I'm trying to pay it forward with this review.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


348 of 361 people found the following review helpful
4.0 out of 5 stars Not the Modem's Fault, but BE WARNED..., March 17, 2012
By 
Cary L. Brown (San Antonio, TX) - See all my reviews
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
... It seems that various ISPs are breaking FCC regulations and Federal Law by refusing to activate some newer modems, in an attempt to force users to use a "leased" modem.

There is an essentially IDENTICAL version of this device, the SB6141, which is the "ISP leased" version of this. You can't buy that, at least not "officially," mind you.

(EDIT - since I originally wrote this, it does seem that it's become possible to buy the "cable operator only" SB6141 directly...)

Time Warner Cable has just had me on the "loop" for the past two and a half hours, and I'm still on hold as I write this. They're telling me that the device isn't on the "approved list" and thus cannot be activated on their system. This, of course, is PATENT NONSENSE. All they require in order to access any device is (a) a device which speaks the same electronic "language" (in this case, DOCSIS 3.0, which TWC Austin supports fully, and brags about supporting fully), and (b) a valid, unique HFC MAC ID code.

The MAC ID is what allows the two devices (the ISP's "source" modem and your modem) to talk to each other, as the ISP needs to know that the ID it's talking to is an ID which it's supposed to talk to, and they need to speak the same language. THAT IS ALL THAT IS REQUIRED ON ANY TECHNICAL BASIS WHATSOEVER.

It is a violation of Federal Law and FCC regulations for an ISP to refuse to service any device which has a valid, unique, and "not stolen" MAC ID and which uses an approved communications protocol.

Those of you who have been told "Comcast won't support this" or, as I just was, "Time Warner won't support this," please realize, YOU ARE BEING ROBBED, every bit as much as if they put a gun to your head and told you to hand over your wallet. It is a CRIME for them to do this.

I am currently on hold, with a "customer advocate" at Time Warner, attempting to get my personally-owned, legally-required-to-be-supported device added to my account.

******

Okay, after a long dialog where I quoted letter and verse of Federal law to the "advocate," I got them to add my modem to my account. And it's working flawlessly.

I would not ordinarily post things not SPECIFICALLY about the device on a review of the device, but in this case, I felt like it was necessary, as some folks may believe they've got a defective piece of hardware (based upon what the ISP tells them) when this is NOT the case.

My ping times have improved... which is somewhat surprising to me, honestly... from about 58ms to around 20ms. I'm not sure why that's the case, but it's a good indication that I have a better connection (lower ping times means less delay between when you send something at one end and when it's received at the other end, basically). My throughput is much more consistent and level, and I haven't seen any of the disconnection errors I've seen repeatedly with my older (DOCSIS 1.0) modem. It seems to be performing flawlessly.

If you have an internet service provider (ISP) who has support for DOCSIS 3.0 (the latest iteration of the modem-interaction-language standard), this is a great choice. Just be prepared to have to argue a bit with your ISP, who seem, in many cases, to be doing everything possible to get you to lease one from them instead of buying your own. Once they give in and agree to activate the MAC code on their system, this will work just fine on ANY current ISP, and will provide full DOCSIS 3.0 support on any DOCSIS 3.0-supporting network.

Don't let the script-reading "support" types tell you otherwise.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


771 of 841 people found the following review helpful
4.0 out of 5 stars Stay with the SB6120, July 8, 2011
By 
Ayame (Denver, CO) - See all my reviews
I have tried both the SB6120 and the SB6121 and the signal levels and speeds were the same on both.
The SB6121 is a little smaller than the SB6120 but runs much warmer than the SB6120. Looks like they tried to cram too much hardware into too small of a space.

My SB6121 did not come with the power save button (it's listed as an optional feature), so about the only difference between the two models is the design. Both the SB6120 and the SB6121 use the same firmware: labeled SB612X.

So unless you want the different looking LED lights and a smaller and warmer box for a higher price, stay with the SB6120.

As far as speeds are concerned: the multiple channel bonding on these DOCSIS 3.0 modems is nice for sustained constant speeds. It also makes it easier for your ISP to enforce the speed cap if they choose to do so (Comcast in my case does). I was getting 20+ Mbps down and 3+ Mbps up on my old Linksys DOCSIS 2.0 modem, however that was the peak when the transfer first started, then it would taper off.
The DOCSIS 3.0 modem stays right at the 12/2 ceiling of my speed tier, but at least the speeds stay right up there and do not drop off after a few seconds.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


269 of 298 people found the following review helpful
3.0 out of 5 stars Potential issue you may face with Comcast, August 7, 2012
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
I had bought this modem about a month back for my connection with Comcast based on all the stellar reviews it has received. However, the modem just didn't stay connected on my line and kept rebooting every hour or two, and sometimes took a good 15 minutes to reestablish a connection. Comcast promptly blamed the modem for my connection problems, but I insisted they have a tech come and inspect the line and as it turned out, the upstream signal power was a tad more than what the recommended power range. It took 4 or 5 tech visits to bring down the power level within the acceptable limits, but the rebooting issue persisted. Comcast finally issued a firmware patch which kind of brought down the frequency of the reboots significantly, but it didn't entirely eliminate the issue.

So I was forced to return this modem and opt for the Zoom 5341 DOCSIS 3.0 Cable Modem 5341J which was recommended to me at the Comcast forums and that modem has stayed connected without a single disconnect ever since I bought it. I would've given the SB6121 a 4 star rating because when it stayed connected, the speeds were pretty good but the fact that the Zoom modem was able to handle signal strengths which this modem couldn't made me pause. For reference, my upstream power levels are around 47dbmv and my downstream is around 5 dbmv, which are within the acceptable limits for a modem to operate.

All these stellar reviews for the SB6121 cannot be wrong, but just be aware that there are issues with using this modem on Comcast (if you are thinking of getting this modem, search on Google for "Comcast SB6121 rebooting issues" and run your own diagnostics to see if your setup is similar to the ones that experience this issue). Caveat Emptor.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


454 of 508 people found the following review helpful
5.0 out of 5 stars Great Modem works with Comcast, June 29, 2011
By 
Falcon (Texas, USA) - See all my reviews
Verified Purchase(What's this?)
Bottom line: this is a great modem and it works with Comcast. Comcast just doesn't have its act together. This modem is not only on their approved list, it has a three star rating, which, according to Comcast, is "the highest and most thorough level of testing." When the cable installer got here (I got a new line installed), he said that this modem was NOT on the Comcast list. Since I still had my DSL line working, I showed him that not only did Comcast approve the modem but that Comcast thoroughly tested it. He had to call the "office" to activate the internet service. The "office" didn't want to set up internet service for this modem; the "office" stated that this wasn't an approved modem. Well, he recalled the "office" and got someone else and they set up the service. I've been happy ever since. I'm supposed to get up to 20 Mbps download and 4 Mbps upload. My computers are connected wirelessly. Speednet states that I am getting 20 to 25 Mbps downloads and the upload speed is between 3 and 3.5 Mbps. I've gotten similar values with speakeasy and other internet speed testing sites. I have a lot of devices connected: three computers (wireless), two TVs (one wired, one wireless), three different game consoles (connected to the wired TV), two Nintendo 3DS (wireless), one printer (wireless), and an iPod Touch (wireless). At times all of these devices are running at the same time - the computers are streaming You Tube videos, one of the TVs is streaming Netflix, etc. The modem handles all of it effortlessly. I'm really pleased with this modem.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


122 of 134 people found the following review helpful
5.0 out of 5 stars Great Modem For DOCSIS 3 / Time Warner, October 23, 2012
By 
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
I bought this modem to avoid the new Time Warner cable modem rental fee in Charlotte, NC. I'm extremely happy with it so far.

The item arrived from Amazon. I unplugged my existing TWC modem and plugged this one in. I then called Time Warner and told them I bought a new modem. They asked for the MAC address and switched my account to the new modem. The call took about 15 minutes and was very easy.

One of the nice things about this modem is it has very detailed status and diagnostic information. While connected to the network this modem is connected to, point your browser at [...] and you can view items like signal strength and the number of channels in use.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


177 of 197 people found the following review helpful
5.0 out of 5 stars Works and Easy Comcast Self Hookup, December 14, 2011
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
12/14/2011 Just received the Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem today. Followed the self-install instructions included with the modem, using Comcast internet, and a Medialink Wireless N router, and was up and running in 20 minutes. Note; also used a Windows OS laptop for the setup, with Internet Explorer.

Here's how my setup went. Disconnect your old modem. Connect the SB6121 modem to your internet coaxle cable. Now connect the ethernet cable to both the SB6121 modem and your computer. Power up the SB6121 modem and wait for all lights to stop flashing (must have solid lights), then power up your computer. Now, open Internet Explorer browser and wait for the Xfinity screen to automatically show up on your Internet Explorer's screen. Enter your Comcast account number and the phone number associated with your Comcast account on the screen, where asked, and press next. The SB6121 modem will then be automatically identified and recognized. Press next to accept the Motorola SB6121 cable modem, then wait a few minutes for the next screen to show up while the information is being processed, then press finished. 3 screens total. Disconnect the ethernet cable from your computer and connect it to your router. Now, power both the SB6121 and your router off and wait 10 seconds. Now, power the SB6121 modem on and wait for all the lights to show themselves. Now, power on your router. You should be able to go online wirelessly. Literally that simple. The Comcast Xfinity self-install screens did not ask me for a MAC address or a serial number. Total time - about 20 minutes to remove the old modem and install the SB6121. Best part, no having to call tech support and no frustration!

I was quite surprised at how easy the SB6121 was to install, as it seems like I'm one of those guys who takes 2-3 hours to hook anything up. Seems like there's always that one thing I didn't know, or think, about, and I'm usually on the phone with tech support for a while having a lackluster time. I replaced an old Comcast RCA modem which I had no problems with, but was tired of renting from Comcast at $84 per year. The SB6121 will pay for itself in a year's time, is a 3 docsis modem versus 2 on my old modem, and works well thus far.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


52 of 60 people found the following review helpful
5.0 out of 5 stars Will Not Work for Comcast Internet and Voice, February 17, 2012
By 
S. Dubya (San Jose, CA USA) - See all my reviews
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
Just wanted to send a warning out there for people like me who are not tech savvy with modems - I found out the hard and long way that this modem will NOT work if you have Comcast internet and telephone. It only has a cable jack and an Ethernet jack (the Ethernet cable is the cable that runs from your computer or router to the modem). For Comcast voice, you need a telephony cable modem that has a cable jack, Ethernet jack, AND a phone jack. I discovered after a visit to Frys that 99.9% of the cable modems do not have phone jacks - 3 of the 4 salespeople I spoke with had never even heard of one having a phone jack. However, the Best Buys that have a Comcast installation center in them DO sell the special telephony cable modem (brand is Arris), but it costs $150. I'm sure I could have found one cheaper online, but I was pretty done with it by then. The rental fee for the Arris modem through Comcast is $7 a month. It would take over 21 months of rental fees to pay off the $150 price, and by then something new would be on the market. So I just bit the bullet and rented from Comcast. Hope this info saves someone else a day of frustration.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


16 of 16 people found the following review helpful
3.0 out of 5 stars The little modem that couldn't (cable modem reboot due to T4 timeout), February 10, 2013
Verified Purchase(What's this?)
This review is from: ARRIS / Motorola SB6121 SURFboard DOCSIS 3.0 Cable Modem - Retail Packaging (Personal Computers)
Summary: this modem is fine if your service is good, but it fails really ungracefully if your service is marginal. While the underlying cause of the issue *is* poor service (which is of course no fault of the modem), fluctuations in signal quality are unavoidable, and how the device *handles* sub-optimal service must be considered in the review process. The fact that the modem reboots with even minimal signal degradation - in situations where other devices do not - is why I have arrived at a rating of 3 stars.

The problem? When your signal levels drift out of spec even slightly, the SB6121 shoots itself in the head and reboots. The error recorded in the logs is "rebooting due to T4 timeout." When it reboots your service is interrupted for 30 seconds to a minute, while you wait for the device to boot and re-register with the CMTS. In my particular case, this behavior happened a few times a day.

By way of comparison, my DOCSIS 2.0 modem never had this issue, and after preliminary testing my Zoom 5341J DOCSIS 3.0 modem does not either (although the jury is still out on that modem's long term performance.

How much this bothers you depends both on how frequently it occurs and on how you're using your service. For normal web browsing, you may never even notice it. But this kind of intermittent loss of connectivity will wreak havoc on things which require a steady connection: online gaming, video streaming, telephony, work VPN, etc etc. If you'd like to know if this is happening to you, the logs are available at the modem's web management UI - look for "reboot" there and check your uptime on the main status page.

I am (sadly) a Time Warner Cable customer. If you do happen to see this behavior with TWC, be warned: they will not do anything to help you, since such problems are generally very difficult for them to track down, and as a rule they are deemed too expensive for them to actually correct. They will either try to up sell you to ultimate/extreme/turbo/etc and claim that this will resolve the issue, or they will tell you to the modem is defective and suggest that you exchange the modem for a replacement.

Do not believe the lies of these charlatans. Being provisioned for a higher cap will do nothing to avoid a time out like this (if anything, pushing more data might exacerbate it), and all SB6121s will handle these scenarios in the same way. A new one will not help.

If you are aware of these issues and opt to try your luck with the SB6121, I recommend that you retain your "rented" modem for a period of time to verify that your level of service is adequate to keep the SB6121 happy. Wait at least a week, and check the logs: if you do not see T3 / T4 timeouts, you are probably fine.

However, if you do see time outs and reboots, you should switch back to your "rented" modem and promptly return the SB6121 within Amazon's return period. Then, you should evaluate your options: if you are paying for and actually need a level of service which requires DOCSIS 3.0 speeds, try a different DOCSIS 3.0 modem such as the Zoom 5341J and cross your fingers. If you do not actually require DOCSIS 3.0 and do not intend to upgrade, though, DOCSIS 2.0 may very well prove more reliable for you and the modems tend to be cheaper. You cannot go wrong with something like the Motorola SB5101U, which should be much more tolerant of failed providers (and also, it should be in extensive deployment, so chances are if *you* see a problem, so will your neighbors - making your provider much more likely to actually start caring enough to fix it).

One final note: I've read that some Comcast customers have received firmware updates which resolve this problem for them. However, be advised: only your cable provider can update the firmware of cable modems, and nobody I ever talked to at TWC seemed capable or interested in discussing firmware updates for my device. If you can get a firmware update that improves the stability of this modem, that's great, but at least with TWC you cannot count on them to do this for you.

Below are some typical signal strength observations at my installation for both this device and the Zoom 5341J (which I replaced it with).

Typical readings on the SB6121 (when operating normally):

SNR: 36-37 dB (four channels bonded)
Downstream power level: 3-4 dBmV (four channels bonded)
Upstream power level: 46 dBmV (single channel)

(Note: these readings are all within spec. When the device reboots the SNR is substantially lower (it's difficult to get precise data since the device retains no long term signal strength data))

Typical readings for the 5341J:

SNR: 40-42 dB (four channels bonded)*
Downstream power level: 2-3 dBmV (four channels bonded)
Upstream power level: 46 dBmV (single channel)

The important thing to note here is the improved SNR of the 5341J. I should reiterate that all of these values are within spec, and you would see absolutely no difference in performance from the 5341J's slightly better readings. However, the fact that the 5341J fares better in normal operation implies to me that the device is of a superior design, and it may tolerate conditions the SB6121 will not.
Help other customers find the most helpful reviews 
Was this review helpful to you? Yes No


‹ Previous | 1 2618 | Next ›
Most Helpful First | Newest First

Details

Search these reviews only
Send us feedback How can we make Amazon Customer Reviews better for you? Let us know here.