Viton® O rings have excellent chemical resistance and can be used at temperature range of between -15°C and 180°C. Although generally more expensive than NBR (Nitrile) O-rings, FKM has found wide acceptance in the aircraft, automotive and chemical industries. 

These O-Rings are the finest available for airsoft use and fit perfectly in all standard sized AEG piston heads and cylinders. 
 
We have two hardnesses available, 70shA (Green) is ideal for general and high-speed use while 90shA (Black) is perfect for extreme pressure DMR builds. 

We recommend lubricating the piston head O-Ring with liquid silicon oil or a thin PTFE based grease.
 
Please note that colours may vary with batch.