CO2 quality is critically important for the health of your air gun. Without clean” reliable 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. Ensure a lifetime of performance with clean CO2. Umarex makes 88 gram capsules” and 12 gram capsules” too. They are all tested and proven clean.