A concusser is a piece of fairy technology that knocks anyone who looks at it out for almost an hour. It looks like a small, silver sphere. When set, it starts ticking for about three seconds to give the concusser's owner a chance to look away, then it explodes and emits a strong flash, knocking anyone looking at it unconscious. Concussers are usually used by LEP agents. It was used in Artemis Fowl by Holly Short in an Italian restaurant after a rogue troll broke in, as well as in The Seventh Dwarf, when Holly Short knocks out some rouge dwarves. Its name comes from the word concussion, which is a type of head injury.