Features:OOTDTY Head-up display the speed, display mph- or km/h, driving time, distance calculate and display, automatically identify time- zone, accurate gps local time display, battery voltage display, etc. Overspeed alarm fatigue driving alarm to ensure your safe in long distance driving. Large Screen Green light display will protect eyes of driver, let driver feel more comfortable, especially for long distance driving. Speed and compass data is from satellites, timely and accurate. In particular, the direction of the compass is not affected by the magnetic field. Compatible with all cars,trucks,bicycle and motorcycle. Specifications: Material: ABS+PCLength: approx 20.6cm/23cmScreen: 8-inch/9-inch(optional)Input voltage: DC12-24VInput current: more than 150mAPower supply: Car Cigarette Lighter-Working humidity: 20%-85%Working temperature: -30℃-80℃Satellite positioning speed: about 1-3 minutes in open outdoor places, no satellite signal indoors (cloudy and rainy days affect satellite positioning speed)Package Includes: 1x Digital SpeedometerNote: Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item.