The Remington Model 870 is a pump-action shotgun manufactured by Remington Arms Company, LLC. It is widely used by the public for sport shooting, hunting, and self-defense. It is also commonly used by law enforcement and military organizations worldwide.

Tokyo Marui invention is a novel new shell based system that allows M870 shotgun to shoot between 3 to 6 BB's at a time. Tthis new M870 also has 3 inner barrels, each equipped with a fixed hop-up. Each shell has a capacity of 30 BBs. The gun only holds one shell at a time, and it only comes with 1 shell on purchase.

The M870 Breacher is a shorter version of Marui M870 with a different grip and pump action grip. There is no stock, the gas tank is a different shape and is stored in the grip.