The M18A1 Claymore is a directional anti-personnel mine

Anti-personnel mine

Anti-personnel mines are a form of land mine designed for use against humans, as opposed to anti-tank mines, which are designed for use against vehicles...

 used by the U.S. military. It was named after the large Scottish sword

Claymore

The term claymore refers to the Scottish variant of the late medieval longsword, two-handed swords with a cross hilt, of which the guards were in use during the 15th and 16th centuries.-Terminology:...

 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

Metre

The metre , symbol m, is the base unit of length in the International System of Units . Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole , its definition has been periodically refined to reflect growing knowledge of metrology...

 within a 60° arc in front of the device.