Helios 44-2 2/58mm, M42 screw mount lens.

Helios-44 is a series of standard lenses for SLR cameras, produced in Soviet Union by KMZ, MMZ, Jupiter from 1958 till 1992 and it is considered to be one of most mass produced lenses in the world. Based on the lens Carl Zeiss Biotar 2/58 , at the beginning was called "БТК" - "БиоТар Красногорский" (BioTar Krasnogorski). A fast 6-element anastigmat, it was available in both single-coated and multi-coated versions.
The name of Helios lenses are usually writen as Helios-44X-N, where X -is the index of lens mount (M for m42 thread, K for Pentax K bayonet, Д for Zenit-D bayonet) and N is a optical resolution index 2, 3, 4, 5, 6, 7 (the higher number the higher is an optical resolution of lens).

Through appropriate adapter this lens can be installed on any modern SLR and mirrorless cameras, such as Canan EOS, Nikon, Pentax, Sony and more. (Adapter not included).

Item specification: 

Lens mount: M39 
Focal length: 58mm 
Relative aperture: 1:2 
Scale of diaphragms: from 2 to 16 
Focusing range: from 0.5m to 20m to infinity 
Light filter mating thread : M49x0.75 
8 Blades

!!!With a special adapter can be attached to modern dSLR and mirrorless cameras!!!
        
Condition:
As you can see in the photos - it's in Excellent Condition. Lenses have cleaning marks that do not affect the quality of the photos. The diaphragm moves nicely at every aperture position. The diaphragm-control ring turns smoothly and accurate.