MTM introduces a new way of storing ammo boxes with its AMMO RACKS. The durable Ammo Racks are available in two different sizes, the AR9M (9mm) and ARRS (Rifle Small). The AR9M comes with eight, P50-9 ammo boxes — offering storage of up to 400 rounds of ammo. The ARRS includes four, RS-50 ammo boxes — holding up to 200 rounds of ammo. Racks may be stored standing, stacked flat or hung on a wall and are ideal for gun safe storage. There are four holes molded into the back of the racks for secure wall mounting.