The Umarex CO2 Cartridge 12 Gram provides consistent power for an airgun. Ensure a lifetime of airgun performance with these clean,12 gram CO2 cartridges. CO2 quality is critically important for the health of an air gun. Without clean, reliable Umarex CO2 power, air guns can break down. Valves clog. O-rings and seals deteriorate. While manufacturers meet standards of size and weight, they aren't held to exacting standards for cleanliness. Even the designs of the seals at the top can vary from one maker to the next, and, if a neck seal is out-of-spec, it can damage a gun's puncture assembly. FeaturesNumber of shots per cartridge depends on model of air gunHigh grade CO2 for optimum performance Tested and proven clean and fit most brands of CO2 airguns