[What is H4 hud] H4 is a upgraded version of the up display, the first color version, with bright and eye-catching colors, a interface design, larger fonts, clearer and smoother graphics, very beautiful, giving people a visual experience. [H4 function display] The up display has multiple functions that can be switched freely. For example: vehicle speed, compass, ambient lighting, number of satellites, automatic photosensitivity, overspeed alarm, mileage switching, etc. You can clearly know your driving speed, time, and direction while driving, and many features of this up display can your driving . [Automatic light sensitivity] The up display can automatically adjust the brightness of the light sensitivity, making the scorching sun clear and the night soft. This is a carefully designed automatic sensing of ambient light based on the principle of photoelectric effect from a professional HUD manufacturer. It is clearly visible during the day and not afraid of being dazzling at night [Automatic alarm function] The model's up display has an overspeed alarm function. If the vehicle speed exceeds the preset maximum driving speed (default 120KM/H), the device will beep. You can set an overspeed alarm value in advance, and when the car exceeds the set speed value, a beep will sound. [Non destructive installation, plug and play] The up monitor is easy to install and can be plug and play through a USB cable, without any complex setup or installation process, simple and very convenient. Using USB power supply, there is no fear of battery loss, cable breakage, or drilling. Colour:Black Material:Plastic Package Contents: 1 * Heads Up Display Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.