The Heckler & Koch MP5 is a submachine gun developed in the 1960s by German firearms manufacturer Heckler & Koch. It uses a similar modular design to the Heckler & Koch G3, and has over 100 variants and clones, including select fire, semi-automatic, suppressed, compact and even marksman variants. The MP5 is one of the most widely used submachine guns in the world, having been adopted by over forty nations and numerous militaries, police forces, intelligence agencies, security organizations, paramilitaries and non-state actors.