Properties:

A circular, single or multipiece, rigid, metallic or nonmetallic item having a centrally located hole with a sharp edge on the inside periphery. It is supplied in various cross-sectional shapes and is designed to be installed in a cylinder, shock strut, or similar device to remove excess oil, dirt, ice, and/or foreign material from a piston, ram, or sliding rod. Excludes packing, preformed; ring, piston; and seal ring, metal.