10mm lens OKS6-10-1M in Arri PL mount
This seems to be widest LOMO (CKBK) lens for 35mm film. Also, this is one of widest lenses with flat field for 35mm film at all. Very rare lens.
Aperture range is T/3.2-16 (no clicks). f/2.8.
The lens has no focusing mechanism at all - it just don't need it having huge depth of field.
Optical condition is very good. You can see minor color change of the rear element coating, and few tiny scratches on the front element.
The lens was tested at studio, and gives excellent image.
But there is one issue that we can't explain and fix - image is great at T/3.2 or T/4, but starts to loose focus if you stepping down further. Very strange behavior since image gets sharper when you are stepping down usually.
So, you'll be able to use this lens widely open only.
Studio techs didn't notice any other problems except of the described above.