CURT Raw Steel Trailer Hitch Ball, 30,000 lbs, 2-5/16-Inch Diameter, 1-1/4 x 2-5/8-Inch Shank Model 40085CURT Raw Steel Trailer Hitch Ball, 30,000 lbs, 2 5 16 Inch Diameter, 1 1 4 x 2 5 8 Inch Shank Model 40085 The CURT 2 5 16" trailer ball does not mess around. Simply put, it is a solid piece of towing equipment that makes all others look like they're just spinning their wheels. CURT 2 5 16" trailer balls are made with expert engineering to be packed with strength and durable enough to withstand the harsh wear of heavy duty towing. Anything your class 5