CNC ERGAL Double O-Ring Ball Bearing AEG Piston Head

FPS CNC ERGAL Double O-Ring Ball Bearing AEG Piston Head Advanced Type (XPAVN).
XPAVN new version with X-RING and one piece plastic shim for AOE.
The FPS ERGAL piston head is a great upgrade that will increase the efficiency of airflow through the cylinder.
This piston head has ports on the front to push out the o-ring as it moves forwards, this ensures that all of the air in the cylinder is being pushed out to propel the BB.