Box gun, also known as shell gun in China, its official name is Mauser Military Pistol. The Mauser factory obtained the patent on December 11, 1895, and officially started production the following year. Because its holster is a wooden box, it is also called a box gun in China. Those with fully automatic functions are also called speed machines, and the Mauser factory calls them rapid-fire machines (Schnellfeuer), which were mass-produced in May 1931.