ZTOP&reg; 2.7Inch LCD HD Dual Lens Dashboard Car DVR Dash Cam and Rear View Camera Accident Recording System Vehicle Data Recorder With DVR/G-sensor/GPS 1: Built-in dual camera, you can shoot at the same time before and after the two-way video 2: Increasing the GPS module can record the full lane track, using random specialized software, you can watch the video on the computer, and through the Internet link Google Maps at same time , showing lane track on the map, the route of the vehicle retrospective. 3: Built-in gravity sensor G-sensor, can record the gravity sensing information and according to the car up and down, left and right, front and rear offset determination, when traffic reaches a certain value is considered abnormal and automatically lock the current video for protection . Using random specialized software, watch the video on your PC, but also saw changes in gravity sensing data to trace the course of gravity in the road