Binokulare Fernrohrlupe (Binocular telescope magnifier) by Carl Zeiss, Jena. 6 x 15 binocular magnifier, circa 1920.

In original case with auxiliary close-up lenses. f = 100cm and f = 35cm.

Serial number: 1075757.

Case dimensions: 20.5 x 12 x 7 cm.

Literature:

Zeiss Historica Society Journal Spring 2002. Pages: 17-19.

Zeiss Handfernglaser 1919-1946, Modelle – Merkmale – Mythos, Hans Seeger. Pages: 529 – 534.

Carl Zeiss company in Jena, Germany, produced telescopes, planetarium projectors, and other scientific instruments.