Latest Airsoft POM piston head from XT. CNC machined from very strong POM material with an aluminium center thread. Thread screw is a few mm longer than standard screws allowing you to add AOE shims should you wish. Comes with a Viton o-ring.
Was tested with 10,000 shots over various builds and showed zero damage. I highly recommend adding a drop of thread-lock on the screw.
Includes thrust bearing.