For the most heavy-duty towing jobs, this heavy-duty 5/8" hitch pin packs an extra punch. It is constructed with an extended length, from high-strength steel, and is tested to 21, 000 lbs. to be compatible with 3" x 3" trailer hitches. The thorough testing done on this hitch pin allows it to keep up with these heavy-duty hitches and tow the heaviest of trailers. This hitch pin is able to fit any 3" x 3" receiver with a 5/8" diameter pin hole. It also features a durable zinc-plated finish to outlast rust, and it has a grooved tip to make inserting the retainer clip easy, from any angle. | Curt Heavy-Duty 5/8" Hitch Pin with Groove 2-1/2" or 3" Receiver