The Russian Zenitar L/Z 50mm f1.7  vintage lens is in good condition, being purchased and posted from Russia four years ago.

I have used it mounted onto the Sony A7 body with an M42 > E mount adapter and it is such a sharp, easy-to-use manual focus lens (especially with focus-peaking on the Sony.) It renders colour beautifully, with a classic vintage look, sharp details and creamy bokeh.
The lens is a solid metal build, focuses easily, and has bright, clean metal aperture blades -please see photos for details of the actual lens. It is reputed to be the Ultron design manufactured in the Russian KMZ factory.

I have to cull my vintage lens collection - sadly...

Details:
ManufacturerCCCP
ModelMC Zenitar-M 50 mm f/1.7
Lens styleNormal
Focal length50 mm
Maximum aperturef/1.7
Angle of view46 o
Closest focusing distance0.45 m
see https://www.pentaxforums.com/userreviews/kmz-50mm-1-7-zenitar-m.html
Comes with both lens caps and a bonus 52mm lens filer for protecting the front element.