There are cameras that you focus setting the distance to the subject in a scale turning one ring around the lens. People who are perfectionists find this exasperating because they don't have anything to support that what they are doing at that moment is correct. The picture will tell that later but that is even worse because then it will be not only an error but a documented error.
For this kind of people this camera offer an uncoupled rangefinder. It means it has a focusing capability. It has a distance measurement device. But they don't go together ! It is possible to measure the distance and then set the correct one on the focusing ring. It is not as convenient as reflex or a coupled rangefinder that you set the focus "while" you measure the distance but it is reassuring.
The central window is the framing one and the two around it are the rangefinder. Zeiss Ikon produced this model from 1954 to 1956. It is light and rigid at the same time. The lens NOVAR, is a three elements lens and it is capable of surprising results compared to others with 4 or more glasses.
Although I was ironic about the uncoupled rangefinder I must say that on the first picture on the left I would hardly get the correct sharpness on Andre's face without its aide. The aperture was full to get the blurred back-ground and any 10 cm or so would make difference.