This is an interchangeable lens with a Deckel mount. I purchased it about 30 years ago at a familiar antique camera shop in London, where I used to go every weekend when I lived in England. You can enjoy a unique depiction that is different from the Schneider-Kreuznach with the same specifications. It has an elaborate construction typical of West German industrial products. It is realistic to enjoy it with a modern digital SLR using a commercially available mount adapter, but I think it's much more wonderful to digitize the positive film shot with the Deckel mount silver halide camera of that time with a decent scanner. Of course, there is no problem with shooting with negative film. The Deckel mount was minor-changed in 1959, and the lenses with "X" at the end of the lens name are for the later mount. Please note that it is not compatible with the old standard Deckel mount (Vitessa-T compatible) for rangefinders. Please also be careful when purchasing a mount adapter separately. I have used it for many years without any particular problems, but I haven't taken any photos in the last few years, so I will sell it as a junk item. The aperture blades and focus ring move without any problems. Please purchase with your understanding. It comes with the original box.