Features: High quality rubber casters for office chairs Heavy duty and safe, fits all office chair bases with mounting holes Twin wheel design improves weight distribution and smooth operation, easy to glide and swivel Swivel and roll freely and more quietly in all directions without the need for maintenance Soft rolling rubber wheel surface guarantees no marks left on carpets or any type of natural and engineered wood floor, tile floor, specialty floor and smooth concrete/asphalt floor Easy to assemble - Just click in Specifications: Material: Steel and rubber Wheel diameter: 73 mm (2-7/8 \") - Approx 3 \" Stem length: Approx 22 mm (7/8 inch) Stem diameter: 10 mm and 11 mm (Look at the picture) Color: Black with transparent Package includes: 1 x Chair wheel Our products are made with the highest quality materials and are designed to provide you with the best possible user experience.