O-ring in NBR,HNBR,EPDM,Silicone,Viton,etc Hardness:ShoreA60,7, ... ,yellow,blue,etc NSF,WRAS,TZW,W270,FDA ItemNBR O-ring DescriptionDescriptionWidely used in bathroom product, valve, faucet, machine, hydraumatic, pneumatic ... Series, ISO 361/1and Customized specificationCertificationISO9001-2008, TS16949, NSF, WRAS, UL, TZW, ACS, FDAMaterialAll raw material meet European REACH, ROHS and ...