There is nothing like the luxury and power that go along with heavy-duty towing. 5th wheel RVs offer a deluxe, home-away-from-home experience unlike any other, while gooseneck trailers possess a strength that far surpasses most other trailer options. As with any trailer, however, 5th wheels and goosenecks must be equipped with the proper lighting and electrical systems, and tend to require even more complex connectors than a standard receiver-type trailer setup. Make things simple with a CURT 5th wheel or gooseneck extension harness. These wiring harnesses are designed to put an extra connector socket in the bed of your pickup truck while still retaining power to the rear connector socket mounted on your bumper. This is done by plugging into the back of the existing original equipment ( OEM ) harness and routing through the body of the truck to a hole in the truck bed, providing a connector that is ready to accommodate your 5th wheel or gooseneck trailer.