Twenty-Five Pack of CO2*Be sure of proper fit and seal with genuine POWERLET 12 gram CO2 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.