Beautiful and ultra-rare FULLY FUNCTIONAL Mentor Goltz & Breutmann Mentor Reflex (1913, Klapp, Folding) camera with a Carl Zeiss Jena Tessar 145mm f6,3 (serial No. 71025), see photos for details. The folding mechanism works very well and without any blockage, the focusing screen opens easily, the focusing screen is clear, the shutter wheel turns smooth, the shutter is functional and works (tested visually without a film holder, the shutter curtain moves accurately and the mirror flips when cocking the shutter), the aperture of the lens works smooth, the lens is clear of fungus.