This CURT adjustable ball mount has a shank size of 2" x 2" and features two different trailer ball sizes to accommodate two different coupler sizes: 2" and 2-5/16". The 2" trailer ball offers a gross trailer weight capacity of 7,500 lbs. and a tongue weight capacity of 750 lbs., while the 2-5/16" ball offers 10,000 lbs. GTW and 1,000 lbs. TW. This special ball mount also features an adjustable shank assembly with multiple mounting holes for varying ball heights. Each trailer ball can be raised to a maximum of 6-11/16" rise or lowered to a maximum of 6-1/2" drop, allowing you to make your trailer completely level in any towing situation. It includes three 5/8" hitch pins for quick and secure installation, and comes equipped with a clevis bar to accept a lunette ring. Also, the adjustable shank can also be used with our tri-ball attachment #45800 and #45802 for even more versatility.