For converting Telescoping Base Stands with Fixed Feet manufactured after 10/02. Kit includes four 5" diameter, non-marking polyurethane casters with toe locks. Load rating for each caster is 250 pounds. Casters have bearings for quiet operation. Casters replace the fixed feet included with Telescoping Base Stands. Installation is required. Not for use with stands that support Purifier Logic Class II, Type B2 Safety Cabinets.