The Industar-50-2 f3.5 is a screw-mount lens manufactured in the soviet union for decades until the 1990's, mostly for the Zenit SLR cameras.
Its predecessor was the Carl Zeiss Tessar design available in M39 (39mm) screw-mount standard lens for the Zorki camera series.
Older variants (ancient Leica lens style) were made by LZOS.