silicone O ring 1.any size for silicon O ring 2.Non-toxic,Waterproof,Dustproof 3Under high wear and pressure 4.OME ... O ring Features:1) AS-568, PG standard and non-standard Silicone O-rings 2) Various colors available, such as black, green ... RoHS ,SGS,FDA,LFGB directive compliant green products3) Available materials: silicone, fluoro silicone, viton(FKM), neoprene, HNBR, NBR+PVC, NBR, natural rubber ...