Patriot Docks Axle Converters - PairThe Axle converters are mounted to vertical support pipe, and accept a wheel axle pipe; both 1 1/2" sch 40 pipes. The axle converters are required to add rolling wheels to a dock. 2-1/16"" i.d. ; For a 4' wide dock use 6' axle, for 8' wide dock use 8' axle.; Patriot Dock components are modular to make it easy to customize the size and configuration for maximum versatility. We have prepared many dock packages which can be combined to almost any layout. Your dealer can put together the plan that works best for you. Check out some sample packages below. You can add more sections or combine packages to make just about any configuration. Patriot Docks are the price leaders in the industry- big volume translates to low costs.