SD card expansion works with up to a 2 gig card (approximately 1 hour of audio and video at best quality) SD card is not included.
Operates on two AA batteries, approximately 2 hours of use on a set of batteries (not included).
Dimensions 4.25L x 1.75D x 2.25H (inches).
Weight is 7 oz total for the camera with mount, batteries and SD card installed
Camera weight is 3.2oz, with two AA batteries and card installed 5.5oz.
Ring Mounts weight is 1.7oz
I've had this unit for a bit and still continuing to pound on it, but I wanted to make sure and tell my experiences so far. Most of the tactical camera rigs I have are pretty fancy, but the recorders are separate from the cameras, causing a lot of wire tango to deal with. The ATC took a different approach and put everything together into one fairly small package resulting in no wires when recording. The only main feature missing is a display to instantly review footage or test your setup.

SPEC:
Waterproof up to 3 meters and shock-resistant for extreme conditions. 
Mount included for RIS/RAS interface system or weaver style mount. 
640X480 VGA resolution at 30 frames per second. 
Both USB and RCA cables are included for easy playback on a PC or TV (NTSC).
Onboard memory is 32mb (good for about 5 minutes).