Relays create the ability to control the power currents for power loads. The relay can functionally switch the load between 2 or more different electric circuits and do so from 1 control signal. By controlling the power signals, you can save on copper wiring in the car, since the relay unit is most often installed in the engine compartment, closer to the power control circuits. That is, it goes to him thin copper wires, from the controls in the cabin, and out of the thick to the power loads in the engine compartment. We offer a high quality product at an affordable price.