SHS had just released these exciting new line of CNC Airsoft AEG cylinder heads with all the features you'll look for on a Cylinder head. These cylinder heads are CNC out of a solid piece of EASTON 7075 aluminum with Italian made double o-ring and full size rubber mat for maximum durability, air seal and stealth / quiet operation. Compatibility: Version 3 (AK, AKS, AKM, AK47, AK74, AK Beta, AK SVD, AK RPK and other compatible AK series Airsoft AEG) Material: Made from EASTON 7075 Aluminum. Processing: CNC process is a process that carves the cylinder head out of a solid block of EASTON 7075 Aluminum, providing maximum precision and durability. Surface Treatment: Military grade anodizing. Features: Double o-ring for maximum air seal and FPS output. Equipped with carefully selected Italian made O-ring. Maximum Air seal, compatible with all major after-market AEG cylinders. EASTON 7075 Aluminum: Much stronger than normal 6061 or 6063 copper. Flat large bottom rubber mat made out of high quality rubber. CNC Cylinder Heads: CNC Cylinder Heads are among some of the best performance and durable for your Airsoft AEG Gearbox.