Partsam 2xRed + 2xWhite 40 LED 4" Round light Stop Turn Tail Backup Reverse w/ Rubber Mount 12V Universal for Trailer Truck Boat Partsam (2Red+2White) 4 inch Round /40 LED lamp function as Stop Turn Tail and Brake Lights, reverse and backup lights. Application: Trucks,Trailers (Boat, Box, Camper, Transport), 4WD, Caravans, Motor Homes, Boats / Marine, Earthmoving & Mining EquipmentForklifts, Buses and Coaches, Camping, Fishing Dimensions: 4 inches; LED Quantity: 40 Diodes. Outer diameter: 137mm (5.4''); Inner Diameter: 100mm (3.94''); Height: 35mm(1.4'') EASY TO INSTALL: 3 Wire Connections - Black Wire is the Ground; Red Wire is the high brightness; White Wire is the low brightness.