The Russian Jupiter-11 is a high quality telephoto lens. It was made in many different mounts - some are well-known (Leica, Contax), some are original Soviet designs (Zenit-4, Kiev-10 etc.). It is an optical copy of the prewar Zeiss Sonnar 135/4.

Specifications:

Focal length: 135 mm
Aperture: 1:4 (settings from 4 to 22)
Field of coverage: 18°
Focusing: 2.5 m - ¥
Filter size: M40.5x0.5 mm
Optical registration (back focus): 28.8± 0.02 mm
Mount: M39x1 mm (LTM). The lens mounts and RF couples with any Leica or Leica copy (FED, Zorki etc.)

The glass is coated; the barrel has polished aluminum/chrome finish

(Source: www.fedka.com)