1Compatibility: OBD2 is only available for vehicles manufactured after 2008. The Gps model is perfect for all vehicles. If your car is not compatible with Obd mode, please use Gps mode. If you are not sure if your car is compatible, please contact us prior to purchase. 2Obd Mode Functions: Obd Mode Hud can display vehicle speed, water temperature, voltage, fuel consumption, rotational speed, clock, single driving time, single driving distance, driving direction, longitude and latitude, altitude, transmission oil temperature, etc. 3Gps Mode Functions: Gps mode Hud can display vehicle speed, voltage, satellite time, altitude, number of satellites, driving direction, single mileage, driving time, up and down slope angle, left and right inclination angle, acceleration test, brake test. 4Easy To Read: The tachometer and speedometer analog displays have a pointer that moves to indicate the value, so you can visually identify the engine Rpm value and speed. Digital speed readouts at a glance allow you to focus on driving without looking down. 5Clear Display: The speedometer features a high definition Tft Lcd screen that displays information in clearly and colorfully with ambient light around the edges. It also has a multi page switching function, allowing you to monitor the speed of the vehicle more comfortably. 6Plug and Play: The unit comes with an OBD2 cable, just plug it into the Obd port to use and read your car data. There are two installation methods, stick to the car center console with brackets, or stick to the front windshield or A pillar with swivel brackets.