Construction These Casters feature two wheels spaced for exceptionally smooth running action. The hard, abrasion proof surface on the wheels is particularly suitable for soft floor coverings such as carpets. This caster is equipped with a brake for increased stability when parked. Sold in Packages of 4 The casters come in packages of 4 casters. Included with the casters are 4 plastic inserts into which the metal caster stem installs.