The Cybergun "High Efficiency" series Airsoft pistol is designed with optimized gas efficiency with an unbelievable / impressive capability of firing up to 170 shots of Airsoft bbs on one single 12g Co2 cartridge, where the first 70 rounds are closed above 350 FPS. In the world of Tokyo Marui system Airsoft pistols capable of firing 20~30 rounds per 12g Co2 cartridge this is an efficiency of over 400%! Externally each Cybergun "High Efficiency" series Colt M45A1 pistol features a fully licensed 1:1 scale authentic replica equipped with a full metal slide, detachable magazine, superior accuracy and much more! After extensive testing, we have been able to compile the chart below for your fps range reference on a single standard 12 gram CO2 cartridge: FPS 370-390, shot count: 1-40 FPS 330-370, shot count: 41-70 FPS 290-310, shot count: 71-120 FPS 170-290, shot count: 120-170 Please note test result can vary based on temperature and rate of fire. Features Ultra efficient gas non-blowback design capable of getting 120 effective shots with just ONE single CO2 cartridge. Full metal slide with light weight polymer frame. 1:1 scale Colt licensed replica with stamped Colt Arms trademarks and engraving. Tri-dot white dot sights allow for rapid target acquisition. Functional thumb safety and magazine release. Integrated 20mm accessory rail allows for easy light, laser or other accessory mounting Textured polymer grip panels Front and rear slide serrations