The Super Ikonta A is part of the trio of rangefinder-equipped roll-film cameras that Zeiss Ikon released in the 1930s.
The A model gives 16 (6cm x 4.5cm) shots on a roll of 120 film, offering the photographer a bit more time shooting before reaching the end of the roll.
Like its other Super Ikontas, this one also uses the rotating wedge prism to achieve correct focus. The photographer then would use the popup viewfinder to compose the scene.
This camera has a left-handed shutter release, which takes a bit of time to use, and the small body also means the photographer must figure out the best way to hold the camera.
When folded, the Super Ikonta 531 is a tiny camera and can easily be slipped into a coat pocket although not a pants pocket because of the weight, although I supposed it could work for some folks.
Much like the 6x9 model, the rotating wedge prisms sit within a small arm that swings up when in use and is swung back down when the camera is folded for storage.
As the years progressed, there were modifications to the design of the top deck and body, but the basic shape never changed. You'll sometimes find this model with a Novar or a Xenar, and the model that is most sought is the one with the coated Tessar. But don't let an uncoated Tessar stop you from buying this camera -- it's an excellent optic.