This Intellinet Network Solutions Caster Wheel Set for 19" Cabinets offers reliability stability and mobility when you need it most. This four-piece set comes with two casters that feature easy-to-apply foot brakes and two free-rolling casters. All four have a hardened-steel zinc-plated axle for durability and stability. The wheels are made from a thick urethane tread wrapped around a 100% nylon core. This ensures easy noiseless mobility and will not leave marks on your floor.