4.5" Car Digital GPS Speedometer Head Up Display Overspeed MPH/KM/H Warning AlarmCar Head Up Display Speedometer HUD GPS Features: GPS Speedometers: Collecting speedometer from GPS satellites in real-time, satellites lock in quickly. Much more accurate than the OBD HUD especially when the car tire is replaced, then engine speed is not accurate at all. Besides, Car Head Up Display Speedometer HUD GPS has the same working logic as speed radar. Universal HUD: The Car Head Up Display Speedometer HUD GPS Compatible with all vehicles, cars, motorcycles, boats, train, and other assets If you use it inside a car, plug it to the car USB port; If no USB port on the old car, then buy a car adaptor for it, or plug it to a power bank. High-Quality Screen: Stand-up display, Projects vehicle speed on the windshield, stand-alone display as the video shows, green color speed display, easy on your eye. Over-Speed Alarm: The default setting of Car Head Up Display Speedometer HUD GPS is 120KM/H or 120MPH. Just need to press the up or down to adjust it. When an over-speed alarm is active, it will beep in 3 times to alert the car driver. If no need over-speed alert, adjust it to an impossible speed eg 999MPH. Easy to Use: Simple Car Head Up Display Speedometer HUD GPS , and good English instructions, get it to use within 5 minutes. Car Head Up Display Speedometer HUD GPS No need professional installation, no wiring needed to the VSS (vehicle speed signal). Car Head Up Display Speedometer HUD GPS Compatible with all cars and trucks, also Compatible with motorcycle and bicycle.Car Head Up Display Speedometer HUD GPS Specification: Type : HUD Car Head Up Display Speedometer HUD GPS Color : Black Material : PC + ABS Input Voltage : DC 5V Input Signal : GPS signal Input Current : DC50-120mA Built-in Battery : None Size : 150 * 16 * 59 (mm)