This is a 1980 copy of the Helios-44 58/2, a Zeiss Biotar copy in M39 mount. Not the commonly found black version. 8-blade aperature. Clean and clear, nice Al finish, smooth operation.
Also include a 39-42 adapter ring so you can use it on Canon SLR and A7, original front cap, cheap M42 rear cap.
Ask: HK$650 only. A good budget choice for fancy bokeh.