The Coby OBD Detection GPS Logger Car Dash Cam with DVR records everything you see and hear. With loop recording, LED night vision, and wide angle recording your car will be well covered. The G-sensors help detect collisions and monitors sudden acceleration. The collision files save from being overwritten. Records exact location and speed and features fatigue driving protection. The on board detection (OBD) measures battery voltage, RPM, Driving Speed, Engine Load, Current Mileage, Rapid Acceleration, and many other things necessary to keep your car running.