A Claymore Mine
The M18A1 Claymore is a directional anti-personnel mine used by the U.S. military. It was named after the large Scottish sword by its inventor, Norman A. MacLeod. Unlike a conventional land mine, the Claymore is command-detonated and directional, meaning it is fired by remote-control, shooting a pattern of metal balls into the kill zone like a shotgun.
The Claymore fires steel balls, out to about 100 meters within a 60° arc in front of the device. It is used primarily in ambushes and as an anti-infiltration device against enemy infantry. It is also of some use against unarmored vehicles.