A flintlock is a general term for firearms that use the flintlock firing mechanism. It can also refer just to the firing mechanism itself. A flintlock uses a piece of flint held in a locking jaw. When the trigger is pulled, a hammer with the flint attached falls, striking a piece of steel called a "frizzen". This causes a spark which causes the gunpowder in the pan (directly below the flint) to ignite. Through a small hole, this ignites the main powder charge in the breech of the gun causing it to fire the round ball, shot or bullet. The flintlock was a very popular type of musket for over 200 years. Flintlocks were available with smoothbore and later rifled gun barrels.