1. high quality O-ring for high pressure oil & air sealing 2. long life, anti-oil, water, grease and high temperature-resist 1. high quality O-ring for high pressure oil, grease& air sealing2. long life, anti-oil, water, grease and high temperature-resist3. material: PU or silicone rubber, NBR, NR, CR, Viton4. series standard products for selecting