3 X 1 1/4 Poly-U/Polyolefin Flat Tread Blue Wheel With Precision Bearing Rigid Caster Plate Mount. Double Ball Raceways Offer Improved Swiveling Action And Durability. Standard Zinc Plated Finish Is Attractive And Corrosion Resistant. Fork And Leg Assembly Designed And Formed For Maximum Durability And Long Term Service.