MC Helios 44-4K 58mm f2

Bought this Russian lens from ebay, it's brand new old stock. Helios 44 is a copy of Biotar lens, and it's famous for its swirly bokeh. Most of Helios 44 variants come in M42 mount, but this 44-4K comes in K mount which is rare. It has aperture lever, so it behaves exactly like SMC K or M lenses. Notice the oval shaped bokeh at the corner of the image.