Jena 50/2,8 M42

I got this lens in a nice condition, there's pain loss, but that's OK.

It looks similar with CZ Jena Tessar 50/2,8.It has leathered finish, which is make different to Tessar

Sources told me that Jena or Aus Jena was East Germany Version of Carl Zeiss. This brand was used only for exported items, which is known has better quality control.
I had CZ Jena Tessar before. It's not as sharp as this lens.Surprise me.
This lens is sharp, even wide open. no joke!