Universal 2-5/16" Replacement Hitch Ball for Turnoverball Underbed Gooseneck Hitch by B&W Trailer Hitches. Solid, machined 2-5/16" ball. Square ball base. This replacement ball for the Turnoverball Gooseneck Hitch is 2-5/16" and is machined for a tight, rattle-free fit. The "corners only" fit of the square ball base in the round portion of the socket allows dirt to fall ...