M7 OBD+GPS dual system car speedometer All cars can be used Notice OBD System(available for cars with OBD2 interface) GPS System(universal for cars,buses,trucks...) The original car is not damaged, the smart is started to stop with the carHUD works: Receive the data from the car and display it on the machine. 1.Multiple functions:Speed,water temperature,voltage,satellite numbers,driving distance 2.Decorative lights:all LED in,you can freely push right to turn off 3.Light sensor:HUD can automatically adjust the brightness according to the environment 4.Speed unit:KM/H=kilometer/hour, MPH=Mile/hour 5.Unit icons:V=battery voltage, C=Celsius,F=Fahrenheit,OBD system,GPS system 6.RPM icon:It is engine speed in OBD mode, and speed progress bar in GPS mode. When button face to windshield 1.Push left:switch between OBD and GPS system within 5 seconds after power up;parameter+. 2.Push right:After HUD displays:switch display mode (standard, athletic, concise);parameter-. 3.Press inward:switch voltage,water temperature,speed,satellite numbers;