Real time speed updates with 10 Hz refresh The GPS speedometer uses a 10 Hz refresh rate GPS and Beidou dual mode chip, delivering speed readings at up to 10 frames per second with zero delay for accurate, real time information. Overspeed alarm for safer driving The head up display features an overspeed alarm that automatically flashes when your speed exceeds the preset maximum, helping you stay within legal limits. Automatic brightness adjustment for clear visibility An ambient light sensor and a definition LED display detect external brightness and adjust the display accordingly, ensuring clear and natural visibility without obstructing your view, regardless of where you place the device in the vehicle. Automatic power on/off with ignition The HUD powers on and off automatically with your vehicle's ignition, providing convenient operation without manual on/off steps. Use scenarios Long highway trips: Monitor real time speed without glancing away from the road, supporting safer, lawabiding driving on open roads. Day and night driving: Automatic brightness keeps the display readable in varying lighting conditions without glare or distraction. Shared or multi driver vehicles: Start the car and the display is ready to use, then automatically turns off when you leave, simplifying everyday use.