If you have an older model air gun or a seltzer charger that uses an 8g CO2 cylinder, then these are just what you need. While most modern air guns use 12g or 88g cylinders, there are some vintage air guns that still use 8g cylinders. Compressed CO2 quality is important for the health of your air gun. Naturally, Umarex manufacturers the best CO2 cylinders for your Umarex air guns to keep them running clean. Ensure the life of your Umarex, or other manufacturers air guns, with high-quality CO2 cylinders.