1. [Hud Hud Digital Speedometer]: Gives real -time feedback about your speed through the head screen GPS, and the head up screen design allows you to avoid looking down to read the instrument and allow you to drive more ly. The GPS head up screen is equipped with a 5 -inch LED display to clearly display the data, in addition to the digital speed indicator, it is equipped with a light detection system that can automatically adjust the brightness and make it easier to read. HEADS Up Display has various data modes that you can choose from, and allow you to get closer to the data you need more accurately. What else? The head screen can also switch between MPH or km/h. Heads screen, your good driving assistant. The first default value of the GPS speed indicator for CAR is 150km/s, 180km/s, 200km/s and the first assumed value of fatigue driving alarm: Alarm after 8 hours of continuous driving. For CAR, both alarm functions of the GPS speed indicator can be adjusted to meet the needs. These two alarm functions can improve your driving factor. Easy to install, installation and play, connect the USB of GPS to the USB port of your car, the car head screen will automatically open and close with car ignition, do not worry about waste waste.