These Prometheus POM Piston Heads are designed for use with the next Generation AK & G36 and the PSG-1 and help to improve your gearbox air seal, thus increasing fps. This allows you to acheive a higher fps with a lowered powered spring thus saving wear on your gearbox.
These POM piston heads are a must when upgrading the fps on your recoil shock rifle.
Bearings are also included with this Piston Head.