MTM Case-GardTM introduces an all new way of storing ammo boxes. MTM Ammo Racks will change and improve the way you organize ammunition. Racks may be stored standing, stacked flat, or hung on a wall Ideal for maximizing gun safe storage Shelves are adjustable for different combinations Four holes molded into the back for secure mount to wall Available in two sizes: AR9M comes with eight P50-9M ammo boxes accommodating 400 rounds of 9mm or .380 ACP ARRS comes with four RS-50 ammo boxes for storage of 200 rounds of 223, 204, 5.56x45 or 6x47 ammo ARRS 17 Fireball,17 / 221 / 223 Rem., 223 Rem. HP,17 MACH 4, 204 Ruger, 222 Rem. Mag., 300 Sherwood, 300 Whisper, 32 Ideal, 32 Win. S.L., 5.56 x 45, 6mm-223 Rem., 6 x 47.