CURT Class 4 Trailer Hitch Ball Mount, Fits 2-Inch Receiver, 12,000 lbs, 1-1/4-Inch Hole, 6-Inch Drop, 5-Inch Rise Model 45446CURT Class 4 Trailer Hitch Ball Mount, Fits 2 Inch Receiver, 12,000 lbs, 1 1 4 Inch Hole, 6 Inch Drop, 5 Inch Rise Model 45446 When you demand more from your towing equipment, CURT heavy duty ball mounts answer the call. For towing those especially heavy loads and bulky trailers, you need a ball mount that knows how to handle itself when the going gets tough. Our heavy duty ball mounts are constructed from quality steel and feature a 2" x 2" shank.