Features: 1. Widely Used: Powered by a 5V USBor cigarette lighter power supply, it can work on allcars\/trucks\/buses\/electric vehicles, etc. 2. Plug Play: Afterconnecting to the power supply, it works directly without any otheroperations. When you start\/stop the engine, the Head-up display turnson\/off automatically. 3. Accurate Speed Monitoring: no jumpingspeed. GPSandBeidou dual chip ensures real-time accurate vehicle speedmonitoring display. 4. User-friendly Display Screen: it isequipped with a Lens hood to block the sun, large font clearlydisplays key data day night. 5. Speed Unit: kmh mph twounit versions; This device is a GPS digital speedometer, the speedis collected from satellites. Therefore, if tested at home or in aparking lot, the speed may not be displayed correctly. Please testoutside the vehicle with good signal. Description: 1. Power Supply: car cigarette lighter\/USB 2. Display Screen Color: white\/green 3. HUD Size: 79x46mm Package Includes: 1 x HUD 1 x Power Cable 1 x Manual