Carl Zeiss Jena 5cm in Contax RF mount, with E-mount focusing adapter harvested from a Contax RF camera. Usually this lens sells without the focusing adapter; this package is immediately useable on any E-mount camera, especially the A7 series.
Optics are excellent with no scratches or blemishes and very slight internal dust. There is one band of dark stuff around the edge of the rear lens (see photo) that doesn't seem to show up on the image.
Aperture opens and closes very smoothly. Aperture blades have some oil.
Focusing helicoid is nicely lubricated. As it is, the lens focuses past infinity; you can fix this by adding a shim between the zebra-patterned part and the harvested Contax metal part, which I haven't bothered to do.
Lens comes with original Carl Zeiss Jena front cap.