The Walther PPK/S CO2 air pistol is a full-metal, semi-automatic BB gun replica. Powered by a 12g CO2 capsule, it shoots 4.5mm steel BBs at velocities up to 295 fps. It features realistic blowback action, a 15-round magazine, and a hidden CO2 piercing mechanism in the grip. [1, 2, 3, 4]