WYING M3 Auto OBD2 GPS Head-Up Display Car Electronics HUD Projector Display Digital Car Speedometer Accessories For All Cars Product Functions Note OBD2 Version: Compatible for: Cars in OBD2 system When you're ready to place an order, but you don't know whether your car is compatible with the HUD, you can contact with us! We're glad to help you! GPS Version: Compatible all cars. OBD2 Version It works when the car is running, and turn off when the car's ignition is off. OBD2 Display data: Speed, coolant temperature, voltage, mileage, clear faulty code. Alarms: over-speed alarm, high water temperature alarm, low voltage alarm, fault code alarm, fatigue driving alarm. Automatically turn on or off: After the engine is turned off for 30 seconds, the HUD will automatically shut down; when the engine is started, it will automatically display after 5 seconds. Our HUD with a switch, which can be turned on and off manually. If you do not drive for a long time, it is recommended to manually turn off the HUD. The brightness can automatically adjust by environment GPS Version It is compatible with all cars! And supports over-speed alarm. Product working voltage is 5V, and it is forbidden to use a voltage higher than 5V for power supply. Some vehicles voltage are highter than 5V, it doesn't matter. Our package included a usb cable, you need to plug usb cable in cigarette lighter, and connect it with HUD. Number of search satellites. Compass: N (North) E (East) W (West) S (South). Vehicle speed display,Speed unit: MPH- mile, KM/H- kilometer. Fatigue Driving Alarm: Fatigue driving alarm is 4 hours, user can freely set this time or turn off this alarm, setting time range: 1-8 hours.