PDI APS 120 Spring - 1joules (13mm diameter & 11mm inner diameter)

PDI APS 120 Spring - 1joules (13mm diameter & 11mm inner diameter) Silicon Chromium Steel Construction Upgrade Spring 120% Power up increased power of 1.0J (approx 325fps@ 0.2g BB ) Supreme Quality Airsoft Electric Gun Spring 13mm diameter & 11mm inner diameter You will get a stable muzzle velocity when install this spring Suitable for Airsoft AEG Rifle Mad in Japan