WEIGHT DISTRIBUTION HEAD KIT: The REESE Round Bar Weight Distribution Head Kit features an adjustable head assembly that works with all Draw-Tite and REESE new style weight distributing spring bars and adjustable weight distributing shanks. HEAVY-DUTY CAPACITY: The kit offers a heavy-duty 12,000 lbs. capacity. REQUIREMENTS: Requires a hitch ball with 1-1/4-inch diameter shank (sold separately). ADJUSTING BLOCKS: The kit features easy-to-use adjusting blocks for easier and faster ball mount angle adjustment. INCLUDES: The weight distribution head kit includes a one-piece cast head, mounting hardware, and angle adjustment serrated washers. It also includes a bushing for a 1-inch shank ball.