Rocket Airsoft Gas Magazine Fill Valve 6.3mm - Gas Grenade

Rocket Airsoft Gas Magazine Fill Valve 6.3mm diameter.  We're not really exactly sure what guns this will fit, but it does work perfectly 1:1 on 40mm gas grenades.  Does not fit Marui, KWA, VFC, WE, KJW, Tanaka, etc.  May fit in some other pistol or gas magazines.  

 For use in green gas gun airsoft magazines/40mm grenades.  SHS OEM