This is a factory Heckler & Koch blued polymer magazine designed for the USP9. The maximum capacity for this magazine is 10 rounds.
Heckler & Koch is a German defense manufacturing company that manufactures handguns, military rifles, submachine guns, and grenade launchers. Heckler & Koch has a history of innovation in firearms, such as the use of polymers in weapon designs and the use of an integral rail for flashlights on handguns.
Originally designed for the American market, the USP (Universal Self-loading Pistol) has found international acceptance as an accurate and ultra-reliable handgun. The USP is available in nine trigger/firing mode configurations and three calibers. 9mm, .40 S&W and .45 ACP.