The digital speedometer for car adopts GPS+BDS dual-mode chip technology, supports 10Hz high refresh rate, and can receive up to 32 satellite signals. It can be stably connected in both urban and rural environments, accurately obtaining real-time speed. The heads up display for cars is compatible with all cars, motorcycles, trucks, etc. with USB ports, easy to install, and the car head up display is plug and play. The GPS speedometer for car has a triple overspeed alarm function, which can set three speed limit values simultaneously. When overspeed occurs, safety is ensured through sound and light prompts. The gps speedometer mph has built-in light sensing components that automatically adjust brightness, providing clear and comfortable display both day and night. Combined with large fonts and anti reflection technology, it further enhances visibility. car hud head up display supports fully automatic start stop, automatically switches on and off with the vehicle's ignition and shutdown, ensuring safe use of electricity. Please note that speed display may be affected by metal window film interference, and slight errors (0.6-1.8km/h) in all GPS devices are normal. It is recommended to use it in open areas to obtain the best signal. Tunnels, underground storage facilities, and rainy and foggy weather may cause brief interruptions. If you have any questions, we will answer them within 24 hours.