[What is H4 hud] H4 is a upgraded version of the head 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 head up display has multiple functions that can be switched freely. For example: vehicle speed, compass, ambient lighting, number of satellites, automatic p osensitivity, overspeed alarm, mileage switching, etc. You can clearly know your driving speed, time, and direction while driving, and many features of this head up display can your driving safety. [Automatic light sensitivity] The head 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 p oelectric 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 head up display has an overspeed alarm function. If the vehicle speed exceeds the preset maximum driving speed (default 120KM/H), the device beep. You can set an overspeed alarm value in advance, and when the car exceeds the set speed value, a beep sound. [Non destructive installation, plug and play] The head 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.