1. Suitable for all vehicles, boats and off-road vehicles2. The signal comes directly from the satellite signal receiver(GPS Speed Sensor)3. The gauge has the advantages of high precision, quick location confirmation and short start up time.4. IP67 waterproof and dustproof gradeFixing dimension: 85mm(3-3/8 inch)Backlight: 7 Colorinstallation method:1.Turn it on, then the meter star to search the signal and LCD will display "gps-",if there is still no GPS signal after three minute, LCD displays "Err".2.Short press the button to change the backlight color: Backlight changed in sequence: red (default) - green - blue - white - yellow - cyan - Purple - (automatic).Automatic: Automatically switch the backlight color every 20 seconds, Cycle switch according to the above sequence.Wiring method1 Black: Ground(-)2 Red: 9-30VDC3 Yellow: BacklightIndicating Range: 0-120km/HModel:CX8129colour:Silver frame + black surfaceMaterial:stainless steel+plasticPackage Contents:1 x GPS speedometer1 x GPS antennaOnly the above package content, other products are not included.Note: Light shooting 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 +/- 1-3cm.