2.5 inch water tempetature auto gauge the light switches between red and white according to the auto headlamp switch 2.5 inch water tempetature auto gaugethe light switches between red and white according to the auto headlamp switchseries:volt/water temp/oil temp/oil press/r.p.m/vacuum/turbo boost/ext.temp/ air fuelif you need more informtion,pls kindly contact me as soon as possible WATER ...