Flak Jacket

Flak jackets are heavy, sleeveless vests made from ballistic nylon, designed to protect the wearer from shrapnel and other low-velocity projectiles.

Flak jackets were originally designed to provide protection from case fragments from high explosive weaponry, such as anti-aircraft artillery ("Flak" is a German contraction of Fliegerabwehrkanone ("aircraft defense gun")). They were issued to U.S. troops in Vietnam to protect against shrapnel from mines and flying slivers of wood from trees hit in combat.