Description [Heads up Display for Cars] This digital speedometer is suitable for all vehicles including cars, trucks, motorcycles, bicycles. Based on the GPS module inside, the mini car HUD display the real and instant speed, fast speed refresh and no latency. [Alarm Function] Over-speed Alarm and fatigue driving alarm to ensure your safe trip. Default setting is 120KM/H or 120MPH and 4 hours of continuous driving. You can adjust it according to your needs. When the product detects speeding, it will beep to remind the driver. [Multiple Functions] This GPS speedometer contains multiple functions: Speed ,Driven distance ,Driving direction ,Automatic light sensitivity ,mile and kilometer ,sound alarm Switch ,speeding alarm ,fatigue driving reminder. The speed unit is KM/H or MPH, and the driver can switch freely according to his own habits. [Plug & Play] Connect the cigarette lighter plug to the cigarette lighter interface, and the installation is very simple and convenient when connecting the cigarette lighter with a USB cable. [HUD Make Driving Safer] The mini head-up display allows you to clearly see the speed and direction you are driving without looking down, avoiding accidents caused by looking down at the speed. Besides, it will automatically adjust the brightne of the display according to the light, so you don't need to worry about the problem of not being able to see the head-up.