GPS Speed Monitor: Car HUD head-up display GPS use at 10Hz high refresh rate + Beidou dual mode chip. The refresh rate is 10 frames per second, and the speed is refreshed quickly and without delay. KMH speed unit is available. HUD: abbreviation for head-up display. The auto HUD head-up display receives signals, connects to your car and displays your car data and driving data on the screen. You can see the data without looking down. More accurate than HUD OBD, GPS Hud has the same working logic as speed radar. USB Plug and Play: Easy installation, plug and play, after plugging in the power, it works directly, no other operations needed. Car HUD head-up display with sunshade, you can see the value well even in the sun. Large font, visible both day and night. Energy saving: automatic on/off. The speedometer turns on automatically when the vehicle is started. The indicator turns off automatically when the vehicle is stopped. Head Up Display Auto HUD has 100% versatility for all vehicles including cars, pickups, SUVs, trucks, trains, scooters, motorcycles, bikes and boats. Note: The device is a digital GPS speedometer and the speed is recorded by satellite. So if you test at home or in the parking lot, the speed may not be displayed correctly. Please test the car HUD screen outside the car with good signal.