The Class III Tri-Ball Trailer Hitch Ball Mount is a receiver hitch accessory consisting of three trailer hitch balls and a shank. It provides three permanently affixed hitch ball sizes, eliminating the need to remove and install different hitch balls or ball mounts. Class III mounts are great for towing things like campers, boats, and trailers carrying ATVs and motorcycles. While these are common uses for this class, it is important that you know the total weight of the trailer and its contents, and that you do not exceed the recommended maximum towing capacity determined by your vehicle manufacturer.