... colors, such as O-ring, U-ring, E-ring etc, its material spec can be silicone rubber,butyl nitrile rubber,nature rubber, EPDM rubber etc, their performance ... and oil-resistant , we can produce all kinds of rubber products with different specifications and property according to customer's ... ±5 shore A, for some special products, can reach ±3 shore AColor For rubber, usually black, for silicone, can be ...