Detonator, DEHT uh nay tuhr, is a small metal or plastic capsule that contains an easily explodable charge. It is used to detonate (set off) larger explosive charges, such as dynamite, mines, and bombs. It contains a heat-sensitive priming charge, such as lead azide, and a base charge of some more powerful explosive, such as RDX. Flame from a fuse or heat from an electric wire ignites the priming charge, which ignites the base charge. The base charge explosion sets off the dynamite, mine, or bomb.