Ergo360 Large Chrome Casters, Chair Wheels with Soft Treads for Hardwood, Carpet, Tile, Etc. Sets of 5. Complete set of 5 large 2.5 inch (65mm) chrome chair caster wheels. Standard size caster stems ( stem length is 7/8" stem width is 7/16") that will fit typical office chairs, stools, etc. Please measure caster stems before ordering, stem diameter must match, stem length can be different. Attractive chair wheels with soft polyurethane treads to help protect hardwood floors. These casters are also great for carpet, tile, linoleum, and most other types of flooring. Extra large chair wheel diameter of 2.5" for easy rolling on hard and soft surfaces.