nosepiece

1. Anything (originally a piece of armour) that protects the nose.

   armor plate that protects the nose

2. An animal's noseband.

3. The bridge between spectacle lenses that rests on the nose.

   the link between two lenses; rests on the nose

4. The part of a microscope that holds the objectives.

5. The outer end or point of a pipe, bellows, etc.

regular