[Source] A laser trip mine consisted of a beam projector affixed to a shaped explosive casing. The laser activated once the trip mine was placed, sending a nearly invisible beam from the charge to the nearest surface that intersects its path, that acted as tripwire to detonate the mine. If the beam were broken or the charge fired upon, the mine would detonate and damage anything caught within its blast radius. This type of mine was often used in places where high security was more important than the preservation of the guarded object.