Rubber O Ring Cheapest!! 1.Certificate:ISO 9001:2000,TS16949 ,ROHS 2.Material:NBR, ... HNBR 3.customer's design is welcome Rubber O Ring Cheapest!! 1 Material :NBR.HNBR2. We also make O-rings by ... . high pressure resistanceE. oil resistanceF. anti-corrosion Rubber O Ring Cheapest!!