The cylinder is made of steel and have been surface treated to ensure low friction and high durability. The placement and size of the decompression holes have been designed to help give maximum compression thus increasing the effect. This cylinder parts are designed to give the best possible air compression and durability. For this reason we recommend always using cylinder parts and not combining or mixing with other upgrade parts as this can affect the result and performance of the upgrade.
For M4A1/SR16, with an internal barrel length of 401-450 mm.