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, clock, driving time, driving distance, number of satellite, driving direction. Compact Design: The compact body suitable for placement. No matter where it is placed, it is clear and natural, and dose not block any sight. Two Alarm functions: It supports overspeed alarm and fatigue driving alarm. The over speed alarm setting range is 0-250KM/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. Automatic Light Adjustment: It can adjust its own brightness according to the environment. Clear display, no glare when driving. Atomatic Turn On/Off: Automatically turn on and off as the car starts and stops. Specifications: Color: black Material: ABS Speed unit: KM/H (kilometers) / MPH (miles) Operating voltage: 5V Product size: 12.8 x 3.6 x 2.5cm Package size: 14.3 x 9 x 5.1cm Package weight: 140g Packing List: 1 * G2 Head-up Display 1 * Micro USB Cable 1 * Non-slip Mat 1 * English User Manual Usage: Plug and play, easy to install. First, plug the supplied USB cable into your car's cigarette lighter. Then connect the head up display. Finally, place the head up display where you want it to be.