Shop DrinkTanks’ 6 pack of CO2 Cartridges, 16 gram, for the perfect amount of pressure in your growler. These can be used with your Keg Cap System. The cap system modifies your growler into a personal, portable keg and works with this easy to use 16 gram CO2 cartridges 6 pack. They are non-lubricated, threaded cartridges.