This is a mint condition Mamiya 645 55mm f2.8 C lens, including both caps and original hard case.
This lens has absolutely minimal signs of use, just a few very tiny dust specks inside. Otherwise it works perfectly and the glass is completely clean and clear (apart from the trace of fine dust); no fungus, scratches, separation or any other problems. The Mamiya hard case is included – this has a little wear on the locking strap as can be seen in the first photo, but is otherwise in great condition.
Now seriously hard to find; this is a really superb lens and you will not find a better example.