Safefit Airbag Vest CO2 CartridgeThe SEAVER gas cartridges are screwed on the SAFEFIT vests. These cartridges allow the vest to inflate in the event of a fall, thus absorbing the shock and protecting you. The SAFEFIT vest must not be used without a gas cartridge. Only a gas cartridge adapted to your SAFEFIT vest can guarantee optimal protection in the event of the airbag mechanism being triggered. Size of Safefit Vest: Cartridge size: XX Small, X Small (Reg & Long) 24g Small, Medium,