Reddit reviews ELING Digital GPS Speedometer Odometer with Backlight 2" Red Backlight 12V 24V

Open a 2" dimension and 2-3/4" depth hole, put gauge into it and fastenHook up easily, 3 wires connection(power, ground, lighting). This is complete unit, can work directly with gps sensor together, not need other sensor cables. Mount the sensor at any position, on or under the dashboard.After connection, 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.It shows Current Speed and ODO, Press the back button to adjust unit(KM/H. MPH, KNOTS)Red Backlight, 9-32VDC(12VDC/24VDC) Working Voltage,1 year Warranty, 100% Waterproof and anti-fogging protection