A stun grenade, also known as a flash grenade, flashbang, thunderflash or sound bomb, is a less-lethal explosive device used to temporarily disorient an enemy's senses. It is designed to produce a blinding flash of light of around 7 megacandela (Mcd) and an intensely loud "bang" of greater than 170 decibels (dB). It was first used by the British Army's Special Air Service in the late 1970s.
