KRexpress Rubber Replacement Swivel Wheel Office Chair, Casters Wooden Floor, Set of 5 [Repress]Color: Black Caster with Black End Cap[Repress] [Repress]Wheel Diameter: 2" (50mm) [Repress]Stem Diameter: 7/16" Grip Ring Type (11mm) [Repress]Stem Height: 0.86" (22mm) [Repress]Outer Wheel Material - Rubber/ Polyurethane