O ring sealing in NBR,HNBR,EPDM,Silicone,Viton Hardness:ShoreA60,70,80,90 Color:black,green,yellow, ... blue NSF,WRAS,TZW,W270,FDA ItemO ring Sealing DescriptionDescriptionWidely ... meet PAHS,NP requirement.NBR,EPDM,FKM,ACM,IIR,Silicon rubber etc. are available.Material usage is based on the final ...