... , SGS Round design silicone rubber jointed rings1.Material: silicone rubber, soft and stretchy, 40shore A2.OD118xID90x1.9mm Thickness3.Raw material for those gaskets: NBR, NR ... , SBR, EPDM, CR, Silicon, FKM, Neoprene, etc.4. All food grade silicone production process confirmed ...