Note: This product working voltage is 5V. Features: Great Compatibility: This head up display is GPS + Beido dual-mode chip. It is compatible with all vehicles around the world. The refresh rate is 10 frames per second, and the speed of the car changes smoothly and continuously. Display Function: This head up display can diplay speed, driving mileage, clock, compass angle and satellite icon. Two Alarm functions: It supports overspeed alarm and fatigue driving alarm. The over speed alarm setting range is 30-250KM/H. Head up display will alarm when the vehicle speed reach to the setting value. The fatigue driving alarm setting range is 1 to 8 hours, head up display will give fatigue driving alarm when your continuous driving time reach to the setting value. GPS Compass: It can dispay all directions, E(East), W(West), S(South), N(North). Easy To Install:Plug and play, Use the USB cable to collect the cigarette lighter. Specifications: Color: black Material: ABS Screen size: 1.8 inch Speed unit: KM/H (kilometers) / MPH (miles) Operating voltage: 5V Product size: 64.7 x 59.8 x 42.6 mm Package size: 100 x 75 x 75mm Package weight: 155g Packing List: 1 * G5 Head-up Display 1 * USB Cable 1 * Non-slip Mat 1 * English User Manual