The CURT weight distribution hitches come with a 2 in. x 2 in. shank and are compatible with Class 3, 4 and most 5 trailer hitches, including Xtra Duty and Commercial Duty (2-1/2 in. replacement WD shank may be required), as well as some RV trailer hitches. While a weight distribution hitch will increase the gross trailer weight capacity of most trailer hitches, the vehicle's weight carrying capacity must be taken into consideration before towing a heavier trailer (NOTE: Never exceed the lowest weight capacity of any towing component).This trunnion bar weight distribution hitch features a heavy-duty formed head and square spring bars constructed from forged steel. It offers a gross trailer weight capacity up to 15,000 lbs. and a tongue weight capacity of 1,500 lbs. It also includes hook-up brackets, spring bar safety chains, a trailer ball and a pin and clip. To protect this hitch from scratching, chipping, rust and UV damage, it also comes with a durable black powder coat finish. For added sway control, this weight distribution hitch includes a sway control unit. While weight distribution hitches are an effective solution for stabilizing and leveling out your towing rig, they should not be considered a sway control. However, when combined with a CURT sway control kit, the WD hitch maximizes its effectiveness in controlling sway. The sway control kit includes a sway control unit, trailer balls to attach to the trailer and hitch, a reinforcement plate and attachment clips.