Линейка бронежилетов (Flak Vest) Армии США и КМП во Вьетнаме.

A flak jacket or flak vest is a form of body armor. A flak jacket is designed to provide protection from case fragments (“frag“) from high explosive weaponry, such as anti-aircraft artillery (“flak“ is a German contraction for Fliegerabwehrkanone, “aircraft-defense gun“), grenades, some pellets used in shotguns and anti-personnel mines, and other lower-velocity projectiles. It is not designed to protect against bullets fired from small arms such as rifles or handguns. However, certain flak jackets are able to sustain certain gunshots, depending on the armor, the projectile, the angle at which the shot was fired (an oblique angle for example), and the range from which the shot was fired. The term “flak jacket“ is often colloquially applied to newer body armor featuring protection against small arms projectiles, but the original usage predated the existence of functional bulletproof vests and the two are not interchangeable in performance.