Safco® Carpet Casters for AlphaBetter Desks, 2.5" Wheel, Black, 4/Set (SAF1210BL) EachSafco Carpet Casters for AlphaBetter Desks These carpet casters are designed for use with AlphaBetter desks to provide mobility and easy reconfiguration. They are made of durable nylon material. To provide a steady work surface, each dual wheel carpet caster has a locking mechanism. Caster Glide Wheel: Caster Global Product Type: Office Furniture Casters Color(s): Black Color Family: Black Weight Capacity: 200 lb (50 lb Per Caster) Material(s): Nylon