Suitable for all vehicles, boats and off-road vehicles The signal comes directly from the satellite signal receiver (GPS speed sensor) The meter has the advantages of high precision, fast location confirmation and short startup time. IP67 waterproof and dustproof rating Stepper motors are used for the whole range of pedometers, a great feature with its lower power consumption, longer life, higher precision, etc. Installation: 1. Turn it on, then it will search for the signal and the LCD screen will display \"gps---\", if there is still no GPS signal after three minutes, the LCD screen will display \"Err\". 2. Short press the button to change the backlight color: The backlight changes in sequence: red (default) green blue white yellow cyan Purple (automatic). Automatic: Automatically switch the backlight color every 20 seconds, cycle the switching according to the above sequence. Connection 1 Black: Ground (-) 2 Red: 9-30VDC 3 Yellow: Backlight Indication range: 0-60 Color: Silver Backlight: 7 colors Material: Stainless steel + plastic Size: 85mm Package Contents: 1 x GPS Speedometer; 1 x GPS Antenna The above package contents only, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3 cm.