O-Ring, Oil Seal, Gasket, U-Ring, Quad-Ring, Glyd-Ring, Step Seal, Mechanical Seal, Extrusion Seals, Rotating Seals and wearable 1.Maunly uses in the oil seal, each king of mechanical seal, on automobile, locomotive, diesel engine and each fuel system.2.each king of chemical seal. 3. Various materials and hardness for your option, including Buna-N (NBR), HNBR, VITON, Silicone, FluoroSilicone, ...