Nikon DW-4 6x Focusing Finder lens mount_Topcon and the Nicca Type 3-S

and the Nicca Type 3-S is a very good Japanese copy of the Leica III- not a bad pedigree

you can stash this holder in a pocket and prolong your battery life

The Nikon 35mm f2 Nikkor-O Auto is a fast wide-angle prime lens for the Nikon F mount

from Germany

which is also called the 16566

Nikon DW-4 6x Focusing Finder lens mount_Topcon and the Nicca Type 3-SNikon DW 4 6x Focusing Finder for the Nikon F3. This finder offers a magnified viewfinder image that is vertically corrected and laterally reversed. Great for macro work, astro, and any other application which requires focus precision. In excellent condition, with rubber eyecup.