Forty Pack of CO2 Be sure of proper fit and seal with genuine POWERLET 12 gram CO2 Forty Pack of cartridges by Crosman. Exacting tolerances ensure consistent performance in virtually all gas-operated guns. We can not ship CO2 using air services. Please consider this when you choose a shipping method. Crosman invented the CO2 Powerlet and is the recognized leader in this field! Put Crosman 12-gram CO2 Powerlets in any airgun that uses 12-gram CO2 cartridges.