This is Ihagee's Zweiverschluss Duplex for 10x15cm sized plates. The lens is a Zeiss Tessar with a lens panel that can easily be removed, so it seems that there was optional lenses available. As to the size of the front lens holder, it is also possible that the other option of lenses was a stereo pair. There are 2 shutters, one focal plane shutter in the back and a dial set compur in the front. This camera is still in need of repair and restoration, but even in this condition it's size and quality is impressive. The quality of the camera design and structure seems better then that of the 9x12 Zweiverschluss, maybe due to thicker wood and metal used in structures.