seal hydraulic cylinder parts 1.O ring hydraulic for best quality 2.Free choice o ring hydraulic 3.Oil saal OEM and ODM seal hydraulic cylinder parts 1. Main materialNBR, also can use Styrene-butadiene rubber,Nitrile rubber, Butyl rubber,PU,EPDM,Neoprene, Silicone rubber, Fluorocarbon, Chlorohydrine rubber and Methacrylate rubber, etc.2. CertificationISO 9001, 14001, Rosh3. Density1.1~1.3g/cm34. ...