The Tengor was a very popular box camera and Zeiss Ikon produced several sub-types over the years. The present one is a Tengor 54/2 built from 1933 to1938.
Manufacturer: Zeiss Ikon, Dresden, Germany
Format: 6 x 9 cm on film type 120 (B II)
Lens : Goerz Frontar 1:11 with two additional aperture settings: 16 and 22
Shutter: short time and "B"
3 Distance settings (for the closer ranges additional lenses are switched into the optical path)
Two prism view finders for portrait and landscape mode.