We have shopped the various type of SHS piston head out there and conducted test. This is the most advanced version with 8 ventilation holes (in opposed to 6), double o-ring (in oppose to one), and ball-bearing. The piston head is constructed out of CNC Aluminum for durability and precision.
Features:
Compatibility: For most Standard Tokyo Marui Style Airsoft AEG Gearboxes
Material: CNC 6061-T6 Aluminum
Manufacturer: Matrix (OEM: PPS / SHS)