Industar-50 M39(RF). Clean and lubricated. 

Very useful video, thanks. Helped me fix an old Industar I have.

Great video, that's a good cleaning

👍🏻👍🏻👍🏻

I have the same lens (from a Zorki 4) but I can't unscrew the bottom part after I remove the long screw from it. It seems to be unremovable. So, is this lens made in two types? One with a removable bottom part and one with a fixed bottom part?

what is the size of the screw driver?