For what purpose the US government first commissioned this device is undisclosed, but it's safe to say that this Small Brass Capsule has a multitude of ingenious civilian applications. Machined from solid brass, and sealed with a watertight gasket, the Small Brass Capsule is an indestructible waterproof container that, in a cinch, clips to any zipper, o-ring, dog collar, or key ring. Use it to stash vital identification, water purification tablets, emergency cash, or medication.