With Adjustable Reflection Board, Speed & RPM & Water Temperature & Oil Consumption & Driving Distance / Time & Voltage Display, Over Speed Alarm, Connect OBD2 Interface, C500(Green), C500(Blue), C500（White)1. Unique design, HD reflective glass, LED stereo imaging, no double image, without reflective film. Plug & Play,easy to use. High tech assisted safe driving. 2. Experience the fun of easy driving, practical functions: driving speed, engine speed, water temperature, battery voltage, fuel consumption, mileage, travel time, clock. 3. Auto power on off. Over speed alarm,high water temperature,low voltage alarm can help to avoid the accidents in advance.