Patriot Docks 24 inch Plastic Dock Wheel Use 2 plastic dock wheels along with PN 10820 axle converters, and HD axle pipe to easily move your dock in and out of the water For use with 1-1/2 in. schedule 40 pipe Outside diameter: 24 in. - Tread surface width: 7 in. Hub size: 4 in. Dia x 7 3/4 in. L Structural strength: 700 lb. capacity per wheel