Here is how these nasty things install: You squeeze a piece of metal into the wire surrounded by a piece of plastic. The metal pierces both wires you are connecting. As a nice added bonus, it cuts both wires a little bit. Oh, and it cuts the insulation of the wires too. No, really it’s a great way to connect wires, especially in a Jeep where you guys are bouncing down trails 1,000 miles from nowhere for days on end.