Aluminium Piston 14 Half Steel Teeth for Airsoft Ver.2 , 3 AEG Marui Cybergun [For Airsoft Only] Essential part for upgrading your Airsoft AEG Aluminum & Steel Construction Compatible with Marui Std AEG Disclaimer: As always, upgrading AEG require necessary skill & technique to dissemble the gearbox, consult expertise if needed Suitable for Airsoft AEG Version 7 Gearbox