O-rings mainly have materials such as silicone, viton, NBR.
silicone material have a good use that it can used in food industry, or more safey field as a seal item. Viton material have good thermostability, corrosion resistance, ageing resistance, etc. to mainly used in aviation, it belongs a special rubber. NBR material mainly has oil resistance, usually, it's used in the place that easy to touch oil.

Of course, we also can supply other materials o rings and seal product
 welcome your inquiry and order, thanks!