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Kidde KN-SMFM-i Silhouette Hardwire Low Profile Smoke Alarm

4.1 out of 5 stars 104 customer reviews

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  • Ionization sensing technology
  • Test verifies alarm operation, hush silences nuisance alarms
  • Sealed rechargeable battery backup included
  • LED indicates alarm condition
  • Kidde's smoke alarms meet the requirements of Underwriters Laboratories (UL), an independent facility that tests products for compliance with widely-accepted safety standards
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Product Description

Product Description



No need to worry about faulty batteries with the Kidde KN-SMFM-i Silhouette Low-Profile Smoke Alarm. This no-fuss alarm contains a rechargeable battery that runs off central electricity and lasts the lifetime of the unit. Dependable and easy to install, this no-maintenance alarm saves on labor and material costs over its lifetime. And because this alarm is interconnect-able, builders and do-it-yourself homeowners will quickly discover this is a must-have for remodels and new construction.

This alarm uses ionization sensing technology. Ionization sensing alarms may detect invisible fire particles (associated with flaming fires) sooner that photoelectric alarms. Photoelectric sensing alarms may detect visible particles (associated with smoldering fires) sooner than ionization alarms. Kidde strongly recommends that both ionization and photoelectric smoke alarms be installed to help insure maximum detection of the various types of fire that can occur within the home.

Rechargeable Batteries Save Money, Time, and Labor
The Kidde Silhouette Low-Profile Smoke Alarm features a rechargeable lithium battery sealed inside the unit that recharges automatically via central electricity. If there is a power outage, the battery will recharge once the electricity is restored. Over the span of the alarm's life, this no-fuss unit saves homeowners money, time, and labor on battery changes. For builders, landlords, hoteliers, and apartment managers, this innovative feature cuts down on callbacks, material, and labor costs.

The battery is designed to last the lifetime of the alarm, approximately 10 years. Once the alarm has reached the end of its life, it will chirp every 30 seconds, letting you know it's time for a replacement.

Product Highlights
  • Rechargeable battery eliminates battery replacement costs
  • Discreet design protrudes less than 1/2" from ceiling
  • Smart Hush silences alarms in non emergencies
  • Cost saving maintenance-free battery is ideal for high-density residencies
  • Initiating alarm alerts firefighters with a flashing LED

Take a closer look at the Silhouette smoke alarm with 360 degree zoom and other views.
An interconnected system provides more warnings in more places in case of fire in your home.
Easy-to-Install Alarm Features a Discreet Profile
The Silhouette alarm's face plate protrudes less than half an inch from the ceiling, making it the most discreet alarm on the market. The encasement containing the sensor and components fits into most round, square, and octagon electrical boxes with 3-1/2-inch hole spacing and a depth of at least 2-1/8 inches. The unit is also compatible with double-gang electrical boxes. Do-it-yourselfers will appreciate the pre-stripped wiring harness, which eliminates the need for a stripper tool, and the tinned strands that increase conductivity and wire nut grip. Once the smoke alarm is installed, simply make sure the unit receives AC power for 24 hours to fully charge the battery.

Interconnect-able for Improved Safety
Fire and consumer experts recommend interconnected alarms for added protection. According to the National Fire Protection Association (NFPA), most Americans feel they are more at risk of being a victim of a tornado than of a house fire. Actually the opposite is true. Fires are more common than any other disaster that strikes a family at home, and can become deadly in minutes.

You have on average less than three minutes from the time you hear a smoke alarm to escape a fire. The sooner you hear an alarm, the sooner you can get out safely. Smoke alarms that link together so that when one goes off, they all go off, are called interconnected alarms. These alarms provide more warnings in more places, giving your family more time to escape a house fire. Houses built after 1993 are required by building codes to have interconnected alarms that are wired into their electrical system.

Thankfully, Silhouette alarms can be linked to create an interconnected system, ensuring that when one alarm sounds, all alarms will sound. Each alarm in the interconnect-able system is equipped with an initiating alarm memory. In the event of an emergency, the smoke alarm that first detects a hazard will feature a flashing LED, allowing firefighters to locate the smoke source quickly and efficiently. All other alarms in the system will sound; however, their LEDs will not flash. This feature is especially useful in apartment buildings, condominiums, hotels, and dormitories. Silhouette’s Low-Profile Smoke Alarm will interconnect to a system containing a maximum of 18 Kidde devices, 12 of which can be smoke alarms.

Trademarked Hush Feature for Convenience
By pressing the Silhouette Low-Profile Smoke Alarm's Hush button, you can easily and safely silence nuisance alarms caused by non-emergency situations, such as overcooked dinners. This alarm's Smart Hush feature has the capability of temporarily desensitizing the alarm circuit for up to eight minutes. This feature is to be used only when a known alarm condition, such as smoke from cooking, activates the alarm.

The smoke alarm is desensitized by pushing the Test/Hush button on the smoke alarm cover. If the smoke is not too dense, the alarm will silence immediately. The red LED will illuminate for 1.5 seconds every eight seconds while in Hush mode. This indicates that the alarm is in a temporarily desensitized condition.

Additionally, the smoke alarm will automatically reset after approximately eight minutes and sound the alarm if particles of combustion are still present. Smart Hush can be used repeatedly until the air has been cleared of the condition causing the alarm. Pushing the Test/Hush button on the alarm will end the hush period.

Meets Industry Standards
Like all Kidde smoke alarms, the Silhouette Low-Profile alarm has been approved by the Underwriters Laboratories (UL), an independent third-party testing laboratory that sets the industry standard for smoke alarms.

About Kidde: A UTC Fire & Security Brand
Renowned for global leadership in fire detection and suppression, Kidde provides solutions ranging from portable fire extinguishers to advanced industrial controls such as flame detection and explosion suppression systems. Kidde is a UTC Fire & Security brand, with a history that's rich with innovations, from the patent of the Chubb Detector Lock in 1818 to the development of the world's first wireless networked smoke detectors in 2004.

What's in the Box
Kidde KN-SMFM-i Silhouette Low-Profile Smoke Alarm with mounting hardware, a 10-year limited warranty and user's manual.

Product Information

Technical Details

Part Number 21007288
Item Weight 8 ounces
Product Dimensions 2.2 x 8.7 x 11 inches
Item model number 21007288
Batteries 1 Lithium ion batteries required.
Power Source battery-powered
Item Package Quantity 1
Batteries Included? No
Batteries Required? No
Warranty Description 10 Year Limited

Technical Specification

Additional Information

Customer Reviews
4.1 out of 5 stars 104 customer reviews

4.1 out of 5 stars
Best Sellers Rank #154,942 in Home Improvements (See top 100)
#106 in Home Improvement > Safety & Security > Fire Safety > Combination Smoke & Carbon Monoxide Detectors
#669 in Home Improvement > Safety & Security > Household Sensors & Alarms
#8,628 in Home Improvement > Contractor Supply
Shipping Weight 8.8 ounces
Date First Available July 7, 2004

Warranty & Support

Product Warranty: For warranty information about this product, please click here


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Customer Questions & Answers

Customer Reviews

Top Customer Reviews

By Tooncesmom VINE VOICE on August 27, 2008
Vine Customer Review of Free Product ( What's this? )
Kidde Silhouette Hardwire Low Profile Smoke Alarm #KN-SMFM-i

The Kidde Low-Profile Smoke Alarm unit is sleek and very low profile, extending only 1/2 inch from the ceiling mount. So much nicer and less observable than the old ones that had begun to yellow.

This is a hard-wired model and requires an electrical box--either the square, round or octagonal box will work, but not the small rectangular one.

Added features:

The unit has an ionization sensor for best "fast flaming" fire protection, an alarm memory--a rapidly flashing LED to alert if alarm has sounded since the last test/reset button was used. (Test/reset button test's circuit's operation and resets memory after an alarm condition.)
Additional features: an LED with four modes of operation--standby, alarm, hush mode and memory set. Nicest of all, a sealed 120VAC rechargeable battery that lasts the life of the unit.

Estimated life of the Kidde Low-Profile Smoke Alarm is ten years.

Installation was easy. We had the correct electrical box in place, so no additional electrical wiring was needed. Make sure your box has 3 1/2" hole spacing and is at least 2 1/8" deep. The wire harness is pre-stripped, so the unit can be placed into use with ease. Installation took only fifteen minutes. Instructions say the unit can be interconnected with up to 24 total devices (12 smoke alarms and 6 heat or CO alarms). Once installed, Kidde recommends the device receive AC power for 24 hours to fully charge the battery and avoid low battery "chirp."
Comment 18 people found this helpful. Was this review helpful to you? Yes No Sending feedback...
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Checkout this installation video. I have replaced most of my smoke alarms with this low profile smoke alarm. I have people come in my house and ask "what's that? a smoke alarm?" It looks much better and no batteries to replace every year!! Too bad Kidde stopped making and selling this smoke alarm. If you can find one buy it. You can also see full video on you-tube, under JoeBrownToolGuy, as Amazon limits the size of the video that can be loaded.
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Verified Purchase
Let me set the scene:
We have just installed 8 of these low profile beauties in our little San Francisco condo. (Apparently we need this many to meet code? Or our electrician went a little crazy...)

2AM - one goes off - and then, ALL of them go off.

No fire, no dust, no steam... just a bad unit. (And don't say it was atmospheric - repeat: we have 8 in our tiny place - the one that falsed is less than 3 ft from TWO other detectors.)

The problem:
False alarm due to a bad unit!
Now a regular 'old' smoke alarm you just yank it down, unplug it, pull out the backup battery, toss it aside, and back to bed. Deal with it tomorrow.

This fancy alarm has a built in Li battery - and cannot be disabled!

............. Let me repeat that. .................

It has a built in battery and cannot be disabled. There is no switch to turn off the unit. Once it's charged that's it. It's on until the battery is dead.

While not being able to disable the alarm sounds like a great feature in principle - that idea falls apart when the unit is broken or hypersensitive.

The solution? Just in case you're staring at the same situation as I was last night... lots and lots of blankets - unplug it, take it down, and wrap it up and place it as far from your sleeping area as possible.

There is a button behind the sticker -- but the label implies that pressing said button voids the warranty. And while I was tempted to submerge the bad detector in a tub of water, I figure that if I want to get my pricey detector replaced under warranty, I'd better follow the rules.
6 Comments 27 people found this helpful. Was this review helpful to you? Yes No Sending feedback...
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Vine Customer Review of Free Product ( What's this? )
Most people know that it is important to replace the batteries in smoke alarms on a regular basis. If nothing else, the shrill beeping of an underpowered unit will cause that. But, did you know that the NFPA (National Fire Protection Association) recommends replacing the detectors every ten years? That is because after that amount of time the probability of failure goes up, and failure during a fire can be catastrophic. This unit will sound an alarm after approximately ten years of service to let you know when it is time to replace it, which is such a good idea I wonder why it isn't in every detector. I suspect the answer is cost, as most detectors are sold by the case to home builders who are looking for the cheapest way to meet code, rather than the best way.

So if your smoke alarms are ten years old (or older), it is time to replace them. When you look around, you'll find that most of them are fairly inexpensive, and very similar to each other. Most of them (like this one) are the ionization type, which uses a very small bit of low level radioactive material to detect the presence of smoke. This type is best for quick, fast burning fires because they tend to put out less visible smoke. The other type use a light with a sensor. When smoke blocks the light from reaching the sensor, the alarm goes off. This type is far less common, and is best for slow, smoldering fires. The light sensors need regular vacuuming, as dust build up on the sensor can cause false alarms. By mixing the two types in a home, or by using units that have dual sensors, you'll be covered for all kinds of fires. Also, both of them will go off regardless of the fire type. The difference is in how quickly they will react to the smoke.
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