Gevaert Gevabox camera Including green flensfilter

A round metal case, with an eye-level plastic viewfinder on top, which takes 6x9 images on 120 film; made between 1955 and 1959 by Bilora in Germany.
Two-speed (1/50, 1/100) shutter + B, fixed focus 105mm/f.11 lens, stop to f.16; eye-level viewfinder of the telescope type.
Shutter works.
Green filter, for example, causes the sky to darken slightly, making clouds easier to see. In addition, it provides a higher contrast.