2" and 2 5/16" Only used 2 or 3 trips each. Not the right height, and I was unable to find a step-up to raise the ball higher, so I had to buy another kit all together. Can sell both or just one. Max Towing Capacity: 12,000 Lbs (solid 2"x2" stock) 150.00 before taxes at Cnd Tire. https://www.canadiantire.ca/en/pdp/integrated-ball-and-pintle-hook-0409088p.html Customer service would not take them back because they got used at least once. Call or Text me at if interested: 250 510 0280