... rubber o ring gasket 1.Material:EPDM,SBR,viton etc 2.Precisely mold design 3.Trial order welcomed 4.OEM/ODM Colored rubber o ring gasket ... Materials advice silicone and rubber(EPDM,NBR,SBR,CR, ... green,red,yellow etcHardness30 to 90 shore A or IRHD, tolerance can be ±5 shore A ... inside, strength carton outside,or as your request. Colored rubber o ring gasket