A hidden diamond ! Most people know MC version of Carl Zeiss Jena Sonnar 135mm is very sharp good lens, but much less people know oldest version like this zebra at least good as or better than MC version.
Compare with quality this lens is extremely cheap, so don’t hesitate buy one and test by your self. Because of its quality won’t be surprised to find even big film production outfits using it, despite its relatively cheap price tag. I found only weakness mechanical build of aperture, this is quite common of “zebra” version of Carl Zeiss Jena lenses. Most of the defected lenses what I saw in my experience were “zebra version”, but don’t worry if looks ok at first time it will works fine for long time. Just need to test carefully before buy if you purchase from remote source, buy this lens from trusted source at this lens is very important.