Power your Gas Blowback Pistol with CO2 or HPA with the Advanced Novelty Tech Co2/Hpa Conversion Kit Fire which can be good for target practice. Booligan Airsoft tells more about this in this video... "If you have a CO2 powered replica like this Colt 1911 Rail Gun, you can now set it up for external HPA or CO2 use using this drop-in product!"