1. If your car is pre-2004 (for US automakers) and pre-2008 (for European/Asian automakers), the protocol is not suitable. Not available. 2. After receiving the package, please test it on your car as soon as possible. 3. According to customer feedback, it is not suitable for some special vehicles, such as electric vehicles, diesel vehicles, hybrid vehicles, pickup trucks, passenger cars, etc. If you still have questions, please contact us before buying, preferably telling us your car make/model/year/agreement before buying. Real 2.6 inch TFT LCD multi-color smart display The first scan will show the vehicle protocol Add functions: Accelerating competitive mode, brake performance test, can read the entire car data stream information. Rich content: vehicle speed, engine RPM, water temperature, Oil tepmerature, intake pressure, voltage, instantaneous fuel consumption, average fuel consumption, driving distance measurement, driving time, low voltage alarm, high water temperature alarm, over speed alarm, engine fault code alarm, eliminate the fault code, freely switch between kilometers & miles Multi-function display mode or simple function display mode can be switched freely to show the above content Two-speed unit: MPH and KMH switch freely Model: P10 - OBD speedometer NO NEED TO BOW View vehicle data such as speed, water temperature fuel consumption, RPM, and more without moving your vision Color: Black Material: plastic Package Contents: 1 x Car HUD Head Up Display