ELING GPS Speedometer Speedo Gauge 0 35 Knots For Boat Yacht Vessel 3 3/8 inches (85mm) 9 32V

Open a 85mm dimension and 70mm depth hole, put gauge into It and fasten Hook up easily, 3 wires connection(power, ground, lighting). This is complete unit, can work directly with gps sensor together, not need other sensor cables. It takes about 30 seconds to get signal in the first time, but less than 3 seconds after that. It gets quicker under a clear view of the sky. Sometimes if signal is missing, pls. reconnect all wires and restart it. It shows current speed and course(not odometer and trip meter). Red Backlight, 9-32VDC(12VDC/24VDC) Working Voltage, 100% waterproof and anti-fogging protection