This is a fascinating niche topic. The is a Soviet collapsible 50mm f/3.5 lens, directly inspired by the pre-WWII Zeiss Tessar. Unlike modern lenses, Soviet optical plants had a chaotic serial number system that can actually tell you when and where your lens was made.
Do you have an Industar-22 with a serial prefix not listed? Email the author. industar 22 serial numbers
Here is a feature developed for a camera wiki, collector's guide, or blog post. By [Author Name] | Optical History This is a fascinating niche topic