They can be original equipment or installed in headers or collectors or reducers on performance vehicles.
Light sensors keep brightness comfortable day or night.
Right ten LEDs are red, left ten are green. Wiring is hooked up with the help of the included three wire plug-in connector. The side facing the viewer is black, but the side facing away has three screw down type wire clamps that work with solid or stranded wire. For this application it is best to use stranded wire with the ends tinned with solder. If the wiring is short or hard to reach, it is easiest to wire just the connector.