Note:This product working voltage is 5V. Features: Safe Driving: The head up display holder shows enough information directly to you, which allowing you to maintain constant focus on the traffic, with no extra distraction. Letting you see the navigation instructions clearly without lowering your head. 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. Simple Function: Simple design, minus complicated functions. This head up display can diplay speed, driving direction and the number of satellites. 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 4 hours, head up display will give fatigue driving alarm when your continuous driving time reach to the setting value. Compass: N (North) E (East) W (West) S (South), After the satellite is found, the GPS light stops flashing and stays on for normal use. Light Sensor: head up display can automatically adjust the brightness according to the environment. Specifications: Color: black Material: ABS Screen size: 3inch Operating voltage: 5V Folded size: 9.5 x 6.2 x 2.7cm Unfolded size: 9.5 x 6.2 x 4.9cm Package size: 14.3 * 9 * 5.1cm Package weight: 180g Packing List: 1 * G100 Head-up Display 1 * USB Cable 1 * Non-slip Mat 1 * English User Manual