In June 1943 the U.S. Army issued the M1A1 Flamethrower. The M1A1 Flamethrower used thickened gasoline as a fuel, and required two men to operate; an operator to wield the flamethrower itself, and an assistant to open the fuel source valves and carry extra fuel, tools, and weapons for the both of them. There were approximately 14,000 M1A1s were produced, and eventually replaced by the M2 Flamethrower.