Amazon.com: Gooseneck Ball Adapter, Kingpin to Gooseneck Ball Adapter Hitch, Used for Tractor-Trailer Fifth Wheels(1-Pack) : Automotive
$147-Flip Over Gooseneck Hitch Accessories | FL2 King Pin for FlipOver Hitch to hook to a inverted 5th wheel hitch, this is NOT a double kingpin. Hitches & Couplers