Tens of thousands of different kinds to select from to have your office Desk/chair sliding easily right and left, install the VXB20040ALT-S. Diameter size of the caster wheel has a metric standard 40mm which is equal to 1.575" inch with imperial units. The thickness of the wheel is 40mm or 1.575" inch. The Caster with the wheel from end to end is 257mm = 10.118" inch. This wheel caster can be mounted using a with the dimensions of 47mm x 47mm and holes distance of 129mm x 74mm. The weehl core material is Acrylonitrile Butadiene Styrene (Plastic) and has a Acrylonitrile Butadiene Styrene (Plastic) tire with a low friction Roller bearing. Each caster will carry the load of 55 lb and is Swivel type. Temperature range is -40 to 180 F. Very important notice, you need to buy the VXB20040ALT-S in order to get one :).