EASY TO INSTALL - No cutting! No splicing! This trailer wiring harness kit plugs into existing factory wiring on your vehicle and equips it with a standard, rear 4-pin trailer wiring connector for plugging in and towing a trailer Connecting Components: 4-Pin Trailer wiring harness is a component for the electrical system connection between the vehicle and the trailer, and the electrical system of the tractor and the trailer is connected together through a 4-pin connector, so that the trailer's brake lights, turn signals and taillights can work normally Stable Operation: By providing a stable electrical connection, trailer tow hitch wiring connector relay harness kit ensures that the steering lights and signaling system of the trailer work properly, improving driving safety at night and in bad weather, which is especially important for long trips Relay Protection: 4-Way Trailer wiring harness connector kit can be used to protect the electrical system of vehicles and trailers from