This is vintage lens made in the former Soviet Union ( USSR ). HELIOS-44m f2/58mm - one of the most common lenses of the Helios-44 series.
Helios 44m is an interesting lens with an amazing picture and fixed focal length 58mm. The focusing of the lens is smooth. The focus ring rotates 220 degrees. When focusing, the front and rear lenses do not rotate. The diaphragm has 8 blades. The iris control ring rotates smoothly, stopping at fixed values. HELIOS-44M 2/58 has a diaphragm mode switch M/A, it can be used to select manual or automatic (semi-automatic) iris control