The DC-1 is a car black box video recorder. It records video & audio on a constant loop & stores it on a standard SD memory card. This camera is fitted with a 3D sensor which measures G-force & will detect an impact. In the event of a collision, harsh braking or acceleration the DC-1 will save a 20 second clip (10 seconds before & 10 seconds after the incident) as an "event". The supplied 4gb card can hold over 200 "events"