The Metral submachine gun is a submachine gun designed by Swiss army reserves officer Gerard Metral intended for clandestine manufacture and distribution during foreign occupation circumstances. It is blowback, select fire, "UZI" type design configuration, and open bolt submachine gun, along with the side folding stock. The design and function of the parts is based on various existing submachine guns (like SUOMI M1931 for the trigger mechanism and Ingram M10 for bolt security etc.), along with some of the authors innovations and solutions, for example the bolt construction and folding stock.