Rubber Stopper 1.Ozone proof rubber seal 2.Good insulation property 3.Certifiication:ROHS 4.OEM/ ODM highly welcom Rubber Stopper1, Terials: NBR, silione, NR, FKM, etc 2, Types of O-ring, E-type, U-type, etc, can make on your size. 3, Different sizes of Oil Seal, Rubber Seal, Rubber Gasket, O-Ring, etc. 4, You could option the color you like on the Oil O-Ring, Oil seal, Rubber Seal, Rubber Gasket ...