It is a semi-automatic shotgun designed and produced by the Italian company Benelli, firing 12 gauge shotgun shells. Originally developed for the US military as a tri service combat shotgun to meet the demands of the US Marine Corps in the early 1990s. Known for its high reliability and versatility, it has been adopted by military and law enforcement agencies in multiple countries. Adopting an innovative dual piston air guiding system, it can adapt to ammunition of different power and ensure stable shooting in various environments. The retractable stock design is unique, making it easy to aim while wearing a gas mask, and the stock can be replaced with a fixed stock without tools.

The M4 shotgun, abbreviated as M4 shotgun, is a semi-automatic shotgun designed and produced by the Italian company Benelli. This firearm is renowned for its excellent performance and high reliability, originally developed as a tri service combat shotgun for the US military. The M4 shotgun is capable of firing 2 3/4 inch and 3-inch 12 gauge shotgun shells, utilizing a unique "automatic adjustment pneumatic operation" system to ensure stable performance in different environments. Its design includes two small stainless steel pneumatic pistons, installed at the front end of the handguard to facilitate the normal operation of the bolt action gun. Widely used in various US military units, it has proven its outstanding performance in actual combat.