Used to move 3 switches from other parts of the truck to an easily accessible location. One has a light bar with a relay, another has a pair of LED lights with an inverted hidden mount on a relay, and one has a fuel heater for my FASS on a relay. It was pretty easy to use. I didn't get the wiring harness but I soldered the wires to the tabs on the switch which worked fine. It was just 16awg wire. Definitely need a wire harness if using larger wire like 14 AWG to be comfortable. I am very happy with them and they are working great so far.