Replacement Caster - 5 x 1 1/4 *HD Casters Have Threaded Stem For Extra Security And Safety *All Single Wheel Castes Come With Removable Bolt And Locknut Allowing Disassemlby For Easy Cleaning And Removal Of Build-Up Grime Thread Or Anything Else That Your Wheel Picks Up During Normal Usage *This Caster System Will Add Longevity To Your Casters *Swivel: Double Ball Bearing With Hardened Raceways For Extra Strength *Cover: Helps Protect Swivel Bearings *Construction: Heavy Guage Cold Rolled Steel Formed For Strength