An East German Zeiss 135mm from Carl Zeiss Jena — the MC version with distinctive DDR rendering.
The Zeiss 135mm f/3.5 MC S DDR is an East German Zeiss Jena medium telephoto — DDR indicates Deutsche Demokratische Republik (East Germany) manufacture. Mount uncertain.
135mm focal length. f/3.5 maximum aperture. MC = multicoating. S variant. DDR manufacture (Zeiss Jena). Manual focus. Mount uncertain.
The Zeiss Jena 135mm f/3.5 MC S is from East Germany's Zeiss Jena optical works — distinct from West German Carl Zeiss Oberkochen. DDR Zeiss lenses were made in M42 and Praktica B mounts primarily. MC multicoating. The 'S' designation may indicate a specific formula. Verify mount physically — likely M42 or Praktica B.
On the used market the Zeiss Jena 135mm f/3.5 MC S DDR is a vintage East German telephoto. Condition checks: MC coating, aperture. Verify mount physically.