Asura 12g CO2 Cartridges - 15PK 12 Gram CO2 Cartridges (Unthreaded) Pack of 15 For compatible airsoft, BB and paintball guns Provides a strong and consistent power source for your airsoft competition game that does not require recharging. You will need a CO2 compatible airsoft gun. NOTE: The 12g unthreaded CO2 cartridges are NOT designed for CO2 Drain Line Cleaner or CO2 Tire Inflator. They normally use 16 gram cartridges instead. Please refer to your product manual and buy the correct type of cartridges for your own device.