Mechanical device for reaching a sound hole that is difficult, or impossible to touch with one’s fingers; A key that closes a hole when manipulated is called an "open key"; A "closed key" opens a hole when activated; NB: These terms should not be confused with "ring" (i.e. perforated) and "plateau" (i.e. non perforated) keys, as used on clarinets, flutes, oboes, &c.

Key cap, Key cushion, Key lever, Spring