This a very fine light meter by Zeiss-Ikon, which works. The black plastic housing dates it as early post war rather than late post war where the housing is cream. On this model the meter needle moves over a scaled 1-16, that value is transferred to the calculator where the shutter speed/aperture can be read. The later post war models have a dial which is turned until an index arm lines up to the needle.Then the shutter speed/aperture pairs can be read.
The meter type is photoelectric. Calibration: Film speed: 3-800ASA. Shutter speed: 1/1000-60s, cine mark at 1/30. Aperture: f1.5-f22. it has a table for DIN and Scheiner conversion on the back imprinted on the back of the black plastic housing..The leather case is fine quality and comes in a russet coloured box with gold embossed lettering.
Inside are two complete instruction manuals - a bit dog-eared but certainly readable.
It is hard to find this model, most of the Ikophots that one sees are late post-war in the cream housing.
Thank you for looking and any questions please ask.