An item designed to choose between firing modes of a carbine, machine gun, submachine gun, automatic rifle or other similar weapons. Modes of fire could include safe (no fire), semi-automatic burst (two (2) or more round burst), and automatic. modes of fire could be between calibers of a single weapon such as between a bullet and grenade or a rifle round and a shotgun round. it is a component of the firing mechanism. differentiated from acuator, gun safety and safety by allowing more than a fire/no fire choice.