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.Flak jackets like these were worn on operations in Northern Ireland.