Plastic Insert for Caster, White, Set of 4, For Rubbermaid Commercial Casters 6173L1, 3424L6, 3421L6, 7805L2, 6111L3, 29973, and some others. For use with Rubbermaid Commercial Products 6173 Cleaning/Maintenance Carts including 6173-88, 6173-47; Utility/Media Carts 1777453, 3355, 3424, 3457, 4091, 4092, 4093, 4094, 4095, 4096, 9T68, 9T72, 9T73, 9T74, 9T76, 9T77, 9T78, 9T92, 9TT94, 9T95, 3421, 9T65; High Chairs 7805, Mop Buckets 6186, 6186-88, 6182; Trolley 4400; and some others. Does NOT fit all Rubbermaid Stem Casters. NOT for use with non-Rubbermaid Commercial casters.