Office Chair Caster Wheels - Set of 15 Wheel - 360 Degree Swivel Simply click into place - Designed to protect hard floors, etc. Black Caster: Heavy Duty Plastic Wheel (Standard). Standard 11mm Stem with Clamp Ring Connector - Stem Length 22mm - Wheel Diameter: 50mm / 2 inch - Wheel Height: 55mm Name: Universal Casters Color: Black Material: Plastic Content 15 * Universal Casters Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.