Suitable compatible with all vehicles, boats and off-road vehiclesThe signal comes directly from the satellite signal receiver(GPS Speed Sensor)The gauge has the advantages of high precision, quick location confirmation and short start up time.IP67 waterproof and dustproof gradeStepper motors used compatible with full range of stepping gauges, great feature with its less power consumption, longer life, higher precision, etc.installation 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 method1Black: Ground(-)2Red: 9-30VDC3Yellow: BacklightIndicating Range : 0-30Colour:blackBacklight: 7ColorMaterial:Stainless steel + plasticSize:85mmPackage Contents:1 x GPS speedometer; 1 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.