These are the original CASE-GARD ammo boxes. The first, the RS-S-50, was designed in the late 1960's. MTM CASE-GARD rifle ammo cases are still the first choice of rifle enthusiasts throughout the world. Made of virtually indestructible polypropylene that will not warp, crack, chip, peel, expand or contract. The CASE-GARD 50 will hold from .22-250 to .308, with each cartridge resting in its own individual compartment. MTM's famous living hinge is guaranteed for 1 million open-closes cycles or ten years. Snap-Lock latch protects contents from accidental spilling. Each CASE-GARD 50 ammo box is supplied with a load label for recording load and sight data