... , x ring , o ring, square ring,,etc for different rubber, likes viton , NBR, CR, etc x-ring, o-ring, square ring,,,etc ... seals, wear rings, piston cups,,,,etc.O-Ring (NBR 72 Shore)O-Ring (NBR 88 Shore)O-Ring (FKM 80 Shore)O ... -Ring (Simriz 75 Shore)O-Ring (FKM / NBR 90 Shore)O-Ring (FKM / NBR 95 Shore)Covered the most BUNA, FLUOROELASTOMER, SILICONE ...