Utility Round Bright 30LED Reverse Backup Fog Marker Light Rubber Mount 4" White Super Bright 4 inch 30 LED Tail/Stop/Turn/Backup Clearance Marker Light Lamp 12V Truck Trailer Round --White Color. 30 High Brightness LED makes you a safe driving on the way. Color: White Led Qty : 30 Diodes. Voltage: 12V. Dimensions: 4 inch. Functions: Tail Lights / Stop Light / Turn / Backup Light, LED Marker Clearance Lamps. Wire Connection Tips: Black Wire is the Ground; Red Wire is the high brightness; White Wire is the low brightness.