When you click on "Add to cart" for this product, Amazon will then suggest you should buy the Transcend Class 10 32 GB SDHC card. DONT BE FOOLED - that is a FULL SIZE SD card - this device takes a MICRO SD card instead.
As far as how the device itself works, I wont know until I return the big memory card and get a little one. Yes, stipulated it says micro card needed way down in the text, but isnt the stuff Amazon suggests supposed to be relevant to the purchase you just made..?
FURTHER FOLLOWUP 3 Dec 2013:
BE VERY careful inserting the SD card; it is very tricky to get it in the slot correctly and very easy to get it inside the case next to the slot and then it is a bitch getting it back out again.
------------------ Followup 10 July 2013:
OK, been using it for a while now. Fairly entertaining toy. As others have already mentioned, "HD" is "BS", its really about 640x480 (each for front and rear). If you want to read license plates, this is not your unit. The only way you'll read license plates with this is if you read-end somebody and submarine under their bumper and their plates are now between you and your own headlights. But having said that, I will keep using it for proof that a light was green or that the guy I ran into ran a stop sign kind of evidence.
You can select it to record front only, rear only and both but it makes no difference to the quality which you choose. You can also DISPLAY front, rear or both (while still RECORDING both) on the built in display. The display shuts off after about 30 seconds but you can turn it back on by pushing the "big" orange button.
It takes some fussing to find a location in a medium sized car where it can see both ways and still not fight with the mirror and sun visors.
The memory card is a bitch to get in and out AND taking it out is the only way to download the videos. Additionally the video is stored on the SDHC in a proprietary format so you have to use their tool to convert it to a conventional format for viewing. It takes about 15 minutes to convert a half hour drive's worth of video.
The buttons are very flimsy and loosely installed. When you go over a bumpy road or lug a manual shift car at low RPM it causes the buttons to vibrate, making a chattering noise which completely obliterates the microphone on the unit. Oh well, my singing isnt that good anyway.
The display is mostly good for verifying that the unit is on or initial setting up the menus, I'd hate to have to try to talk my way out of a ticket by showing it to a cop; If I need traffic law evidence I plan to not mention the unit at all, take it home, download/convert the video and then take THAT to court or email it to the cop as appropriate.
It has a G-sensor built in which marks a video clip for retention so that an important video doesnt get auto-written over, I guess thats a good idea, but on the "medium" setting it thinks switching on the radio while sitting at a traffic light is enough G force to mark a video for protection.
As always the Engrish owners manual is mostly useless, but then what manual isnt these days; heck even the manual for the CAR is mostly 400 pages of "dont operate the car inside the garage", "dont roll the window up while your head is sticking out" and "dont drive underwater without wearing a seat belt" useless rubbish anyway; designed to protect the manufacturer from the lawyers of stupid people. As a society we'd probably all be better off if they DIDN'T warn people not to roll the window up with their head sticking out...