D1 Car OBD2 HUD Head-up Display GPS Speed Meter Speed Voltage Water Temperature Speed Alarm 1. HUD short for Head Up Display,the main function is to reflect the car dashboard information (e.g. speed, RPM, water temperature, voltage, trip distance etc),and keep the driver eyes always on road to avoid the dangerous of lowering down head to read the instrument. 2. OBD mode display information: display: vehicle speed, rotation speed, fuel consumption (instant fuel consumption, instant fuel consumption per 100 kilometers, average fuel consumption), water temperature, voltage, clock, driving distance, driving direction, altitude, number of satellites, speed icon, 100km acceleration test Alarm: overspeed alarm, speed alarm, fatigue driving reminder, high water temperature alarm, low voltage alarm, engine failure prompt, free switching between kilometers and degrees Celsius and Fahrenheit 3. GPS mode Display information: display: vehicle speed, local time, voltage, driving time, driving distance, driving direction, altitude, number of satellites, speed icon Alarm: overspeed alarm, low voltage alarm, free switching between miles and miles 4. Navigation method: You need to download the WiiYii APP software, the HUD and the smart phone are connected with Bluetooth wirelessly, and the navigation information is displayed synchronously through the APP. 5. Working voltage: 5V~18Vdc (12Vdc200mA)