1.Double Tow Ball Mount with 2 hitch ball 2. Ball Sizes Shank L Capacities Double Tow Ball Mount is one kind of towing products.There are two types hitch ball sizes 1-7/8",2" hitch ball and 2",2-5/16" hitch ball* Item# Ball Sizes Shank L Capacities #111000 1-7/8",2" 6-1/2" 2000, 3500 lbs#111001 2", 2-5/16" 6-1/2" 3500, 6000 lbs ItemSizeCapacity1110001-7/8''3500lbs1110012-5/16''6000lbs