Features: Head-up display the speed, display mph- or for km/h, driving for time, distance calculate and display, automatically identify time- zone, accurate gps local for 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. for all for cars,trucks,bicycle and motorcycle. Specifications: Material: ABS+PC Length: approx 20.6cm/23cm Screen: 8-inch/9-inch(optional) Input voltage: DC12-24V Input current: more than 150mA Power 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) Note: 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. Package includes: 1x Digital Speedometer