12 gram C02 cartridges are still very common in the paintball world. They are used for mostly pump and pistol type paintball guns as well as Airsoft guns and C02 powered grenades.
A 12 Gram CO2 Cartridge is a simple disposable cylinder that when punctured by a pin, releases the Compressed C02 contained in the cartridge. Depending on the gun, most of these cartridges can get you up to 25 shots without having to change cartridges.
You can purchase the 12 gram CO2 cartridges individually, or in bulk - 5, 10, and 25 pack. The 12 Gram CO2 Cartridges are ideal for propelling any Pump gun or paintball pistol at very reasonable prices.