These casters are a great option for swivel office chairs that are used on hardwood, tile and concrete floors. The polyurethane rubber outer wheel ring helps to reduce slipping compared to a plastic caster and is gentler on hard floors. Casters have been tested for a 500-pound capacity. Sold in set of 5 casters. 2.375-inch diameter wheels. Caster stem measures 1.1 cm diameter x 2 cm long. Shipping weight 1 pound. PRICE INCLUDES SHIPPING! IN STOCK!