GN6 - 4.5" square tube with kingpin. Pull your gooseneck trailer with a semi-tractor or pickup mounted fifth wheel. Simply replace the coupler with a king pin. Easily switch back and forth. 2? SAE king pins are the industry standard and are suitable for use in all over-the-road applications. 30,000 GWR, powder coated finish, 10" round bolster plate. Package quantity:1 Product Type:TOW HITCH No batteries required Country of Origin:United States MODEL NO - GN6