CURT Double Lock Offset Gooseneck Ball, 4-Inch Offset, 20,000 lbs, 2-5/16-Inch Diameter Model 60602CURT Double Lock Offset Gooseneck Ball, 4 Inch Offset, 20,000 lbs, 2 5 16 Inch Diameter Model 60602 While the basic CURT gooseneck ball offers all the towing power needed for towing that heavy duty flatbed trailer, a standard trailer ball does not always provide the perfect fit for your unique application. The CURT offset gooseneck ball is the fast, convenient way to offset the placement of your gooseneck hitch by 4". If you have owned your gooseneck