The Alera Casters for Wire Shelving set includes 4 steel casters, with 2 locking and 2 non-locking options. Designed specifically for Alera wire shelving, these silver casters have a maximum weight capacity of 600 lbs each. The compact size of 7" in height and 13" in both length and width make them suitable for easy mobility and storage. Built to last and meet the needs of material handling in a business or industrial setting, these Alera casters are a reliable and durable solution.