CO2 chargers airsoft operating with a 12gr capsule. Used on replicas such as the M1911, the MEU, the SP2022 or the CZ series 75. You will find Cybergun brands of chargers, KWC, ASG, WE or KJ Works. We recommend not shake caspule up, just enough to seal a way as not damaged gasket charger. Maintains a recommend an application of silicone or Teflon spray on the spring and the location of the Co2 cartridge helps maintain the charger.