Although rubber O-rings is the simplest parts in the field of seals, it’s the best and most efficient seals. The structure of sealing part is very simple, for this reason, it could be used even in limited spaces. Furthermore, it could be used reliably as movable and immovable seals in the circumstance of big pressure and high temperature. If reasonable design, o-rings have very long life. O-rings could not only be used for its good sealing performance,but also for its mechanical performaces, it is being used widely in drive strap, tyre, controlling equipment and vibration absorber. It could be made by many kinds of raw materials,such as NBR, SBR,Silicone,FPM, ACM.