We are offering CO2 gas cartridges which are small, disposable cylinders filled with carbon dioxide gas that is used in a variety of applications, including fire extinguishers, beverage dispensing systems, & pneumatic tools. The cartridges are made of steel or aluminum and are filled with compressed CO2 gas, which is released when the cartridge is punctured. CO2 gas cartridges are commonly used in portable fire extinguishers, where they are used to quickly suppress fires involving flammable liquids and electrical equipment.