CURT 56080 7-Foot Vehicle-Side Truck Bed 7-Pin Trailer Wiring Harness Extension: Automotive. Buy CURT 56080 7-Foot Vehicle-Side Truck Bed 7-Pin Trailer Wiring Harness Extension: Wiring - ✓ FREE DELIVERY possible on eligible purchases. Routes existing 7-way RV blade socket into full-size pickup truck bed . Universal size fits any 7-way RV blade socket . Allows for easy connection of 5th wheel or gooseneck wiring . 7' extension length accommodates virtually any size truck bed . 7-way connects tail, brake, reverse, turn signals, brakes and auxiliary power . 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 / gooseneck extension harness.This original equipment (OEM) extension plugs into the 7-way RV blade at the rear of your truck and routes to the truck bed, providing a connector that is ready to accommodate your 5th wheel or gooseneck trailer. It is designed to work with any standard 7-way RV blade connector and comes in a length of 7'. When you need a towing electrical solution that allows you to switch back and forth between your receiver hitch and specialized trailer hitch, CURT gets you plugged in. . . .