this is best helmet cam could help you enjoy the exciting outdoor sports fun and avoid injuries
-G-Sensor
DVR will save videos as undeletable files when gravity acceleration, any
accident happens.
-SOS function
Under recording mode, press Down button momentarily to activate SOS
function, the current video will be saved as undeletable file.
-Silent Video Recording
Under recording mode, short press up button momentarily to off microphone,
the microphone icon on screen will change to No voice icon. Do not worry
about your secret talk.
-Image Rotation Function
When the camera need to be mounted upside down, turn on the Image
Rotation, the video footages and pictures will be upright.
Specification:
Model: AT91
Sensor:1.3Mega CMOS
Lens: Fixed Focus,120 degree under full hd mode
Image size: 12Mega 4000*3000
8Mega 3264*2448
5Mega 2592*1944
3Mega 2048*1536
Resolution: Full HD (1920*1080) 25fps
720p (1280*720) 30fps
VGA (640*480) 60fps
Audio: Built-in Microphone
Storage: Support Micro SD card up to 32G(not included)
File Format: JPG/AVI
Battery:800MAH rechargeable Li-ion battery
Screen:1.5inch high definition screen
USB:USB 2.0
HDMI: Support
AV OUT:PAL/NTSC
Silent video recording: Support
SOS recording: Support
G-sensor: Support
Image Rotation: Support
Waterproof: waterproof underwater 60meters
Item Size(Approx.): 8.5 x 4.2 x 7.5cm(L*W*H)(Includes the waterproof case)
Item Net Weight: 134g

Accessories:
Bike bracket
Universal bracket
Pedestal bracket
Helmet mount
Base mount
Base bracket
Elastic band
3M pads
Nylon belt buckle
AC charger
USB cable
HDMI cable
TV cable
Waterproof case