Fits standard AK mounts and presumably SVD style mounts. 
Magnified optic works as it should with the appropriate reticule and cyclic markings.
The previous owner has dremelled off what I assume was the illumination bulb or something (correct me if I'm wrong, I'm not too clued up on optics and scopes) hence the crusty circle of bare metal on the underside of the optic.
Presumably this was done to allow it to mount on an AK as it would have interfered with the top cover otherwise.