Industar-96U
lens for enlarger, #8703
50 mm, 1:3.5, M39 mount, 
Feodosiyski Optical Plant  (FOZ), "OPTA" trademark, Feodosiya, USSR

Very good condition. Lens is clear, does not have any scratches or fungus. Inside there are microspecks of microdust. Body has tiny, almost invisible signs of age. Aperture ring rotates easily and has a small backlash.

This is a lens for enlargers for frame size 24x36mm. 
"Industar-96U" was produced at FOZ (Feodosiya) since 1980. Its variant I-96U-1 was produced since 1985. Difference is in the changed body design.
It is a lens for enlarger so it does not have a focusing ring. Focusing is done when moving the camera or enlarger with lens together. To use with camera you need macrorings or bellows.
Thanks to its resolving power and sharpness it is now often used as macrolens.
Lens is very sharp, even at f/3.5, giving a nice bokeh. Lens does not work in contre-jour, but does not have any chromatic aberrations, vignette or distorsion. 
This lens is very-very small and lightweight. You can easily put in your pocket.
Lens has one-layered antireflection coating.
Its price in USSR was only 9 Soviet Roubles (with average salary about 120 Soviet Roubles per month).
Also "Industar-96U-2" with lighting of aperture scale were produced since 1985.
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Characteristics:
Lens s/number - 8703
Number of lenses - 4 in three groups, Tessar.
Angle of view - 38o
Number of aperture blades - 5
Limit of aperturing - 1:3.5 (max), 1:11 (min)
Resolving power - (centre/edge) 60/24 lines/mm
Minimal distance of focusing - 0,29 m
Type of thread - M39
Type of thread for the nozzles -  cannot be mounted
Dimensions (mm): 47*47*40
Real focal distance - 53,4 +/-0,5 mm
Mass - 61 g
One-layered anti-reflection coating