Caster Wheel Type Tread on Core Caster Wheel/Tread Material Polyurethane Caster Frame Material Polymer Caster Mounting Height 6 3/8 in Caster Mounting Type Stem Caster Stem Length 2 3/16 in Caster Wheel Diameter 5 in Gray Nickel-Plated Overall Height 8 9/16 in Overall Width 2 3/4 in Compatible Manufacturer Model Number Industrial Plastic Shelving Racks Includes Bumper