o-ring material for NBR,HNBR,CR,EPDM,SBR,SILICONE etc.Can choose on your requirement. o-ring1.Several material for :NBR,HNBR,CR,EPDM,SBR,SILICONE etc.Can choose on your requirement.2.Different sizes and colors are available.3.Apply for:Auto,machinery,valves,air condition.4.High quality with competitive price.