M18A1 Claymore Mine
The Claymore was developed to defend against mass attacks. Seven hundred steel balls are embedded in C4 Explosive. The mine is shaped like a curved rectangle. This convex design allows for a full sixty-degree pattern of deadly steel balls when the mine is activated. The blast mows right through elephant grass.
For an even more devastating effect, a solid material or tamp is placed behind the mine. It was not only used defensively, but in ambushes. One deadly method was to detonate mines shoulder high on a tree, and then a second or two later, detonating additional mines at ground level. A friend of mine kept one in the top flap of his rucksack to use as a last resort.
The mine can also be pried open and the C4 used to heat up food. The Claymore was used extensively by Rangers during the Vietnam War.