Fabricated using extra heavy wall tubing for maximum strength. This coupler latches when the trailer is lowered onto the ball. It also has a molded hitching guide to make coupling easier. To uncouple, you simply pull a release cable located near the trailer jack handle. The GN8 coupler has a rating of 28, 000 pounds. Short Bed Extended Couplers come with all necessary hardware and coupler release cable. Installation takes about half an hour. Part measures 4? outside dimension. Make sure it will fit as many of the China made tubes are not all sized consistently and many are under sized. PopUp will assume no responsibility for returns when incorrect measurements are taken. | Popup Towing Products LLC SB3-6 Gooseneck 6" Offset Coupler, 4" Square Tube