Specifications and Features: - Product Group: Air Pistols - Brand: Heckler & Koch - Velocity (FPS): 400 - Caliber: 0.177 (4.5mm) - Ammo Type: Steel BBs - FPS w/Lead Pellet: 400 - Barrel Length: 4.5 - Total Length (inches): 7.5 - Capacity: 22 - Barrel Type: Smooth - Front Sight Type: Blade - Fixed - Rear Sight Type: Notch - Fixed - Action: Semi Auto - Safety Type: Manual - Power: CO2 - Trigger Action: Double - CO2 powered BB guns are great fun for plinking and target shooting. Check out this HK USP. It holds 22 rounds in a heavyweight magazine that also houses the CO2 cylinder that powers this BB pistol. It has an ambidextrous magazine release integrated accessory rail and realistic hammer movement. This is a great practice pistol for 9mm USP owners. For just pennies a shot you can shoot for hours. - UMAREX holds the worldwide exclusive HK-trademark and exterior design copy license for use with this UMAREX product granted by HK Inc. U.S.A.