During the 1930s, Zeiss Ikon (ZI) made a wide range of miniature cameras for the 35mm film format. Most cameras used the standard 24×36 mm frame size, like the Contax, Nettax and Super Nettel. However, the ability to take images in fast sequence was a popular marketing element at the time, and several fast-operating models were made. Among these were the Otto Berning's motor-driven Robot cameras as well as the ZI lever-operated Tenax I and Tenax II. These have the smaller square format of 24×24 mm, enhancing faster frame advance.

The Tenax II produces 50 square exposures on a standard length of 35mm film. It has a Compur Rapid shutter, situated just behind the lens, with speeds from 1 to 1/400 second. The camera is wound and the film advanced simultaneously depressing the large lever on the right-hand side of the lens. 

The Tenax II has a proprietary bayonet lens mount as a provision for using different lenses, but only a small selection was made available during the few years the camera stayed in production, halted by Germany's war efforts. A small round window in a lateral extension on the lens barrel is aligned up in front of the camera's right-hand rangefinder window. It contains a pair of contra-rotating glass wedges synchronized with the lens focusing lever that provides accurate focusing by aligning a superimposed tinted image with the image in the viewfinder.