The raw material of O-ring is 100% rubber,It plays a role in sealing and be a green product.It certificates SGS,FDA,RoHS. Rubber O-ring:1.Material: Rubber2.Certificate:SGS, FDA,RoHs3.Color:any color is available.4.Design:according to your requirement,available in various sizes.5.Loading Type: all kinds of loads6.OEM order highly welcome. Rubber gaskets