About this item Powered by a 12-gram CO2 cartridge (CO2 NOT included) Rifled barrel can fire either .177cal/4.5mm BBs or pellets (NOTE: Use round BBs or flat-head pellets only) Shoots .177 caliber steel BBs at up to 490 FPS Accessory rail for easy mounting of lights, lasers and other accessories Metal slide; Slide moves with blowback action after each shot