USSR Helios  58mm 1:2 44M lens, A/M aperture suitable for M42 camera mount 

possible traces of rubbing! and dust particles

great lens! mechanics work great!

Characteristics:
Format: mirror 35 mm.
Type: Fixed focal length (fixed)
Focus: manual focus
System: M42
Optical design: 6 elements in 4 groups
Focal length: 58mm
Aperture: f/2.0 - f/16
Blade aperture: 8
Filter Thread Diameter: 49mm
Weight: 270 g
Length: 42mm