Suitable for all vehicles, boats, and off-road vehicles. The signal comes directly from the satellite signal receiver (GPS Speed Sensor). The gauge offers high precision, quick location confirmation, and short startup time. IP67 rated for waterproof and dustproof performance. Stepper motors provide full-range operation with low power consumption, extended lifespan, and high accuracy. Installation: 1. Turn on the device to search for signal. The LCD will display "GPS". If no GPS signal is received after three minutes, the LCD will display "Err". 2. Short press the button to change the backlight color. Colors change sequentially: red (default), green, blue, white, yellow, cyan, purple, then automatically cycle every 20 seconds. Wiring: - Black: Ground (-) - Red: 9-30VDC - Yellow: Backlight Indicating Range: 0-30KM/H Color: Silver Backlight: 7 colors Material: Stainless steel + plastic Size: 85mm (3-3/8 inch) Package Contents: 1 x GPS speedometer 1 x GPS antenna Note: Light and display differences may cause slight color variation between the image and actual item. Measurement error allowance is +/- 1-3cm.