Smooth rolling wheels offer substantial dock cushioning and feature molded-in valves to adjust the level of firmness. Heavy-duty hot-dipped galvanized hardware mounts securely to the dock. 12" and 18" wheels use a large 2" diameter axle housing for maximum strength. Made in the USA Brackets & wheels are not interchangeable. Replacement wheels include cap & washer Up to 20' boats | Taylor Made Replacement Dock Wheel White 9"