Called the shield boss, or umbo, is a round, convex or conical piece of material at the centre of a shield used in battle
Coarse adjustment knob.
Focusing, its called a focusing knob.
the notorious shield tax was simply called shield tax
This is called a shield volcano and an example would be Hawaii.
The knob used for pitch adjustment or tuning on the violin is called the "peg".
it is called fibrin
its not its called a shutter
It is called a continental shield.