Forge Kingpin to Gooseneck Ball Adapter with 3″ Raised Reinforced Rib, for Tractor or Trailer Fifth Wheel, 30000Lbs GTW, 2-5/16″ Ball, Gooseneck Ball Hitch Adapter Replace#2085295,Four Washer. 5th Wheel Lube Plate: Each of our adapters is equipped with one 5th wheel lube plate.