This is a really excellent condition Mamiya 645 55mm f2.8 N lens, including both caps.
This lens is in great condition. Cosmetically it has minimal signs of use, with just minor paint loss on the lens mount, as almost always with these lenses. Mechanically no issues; optically it is as good as you will get apart from the usual few tiny dust specks which will have no effect at all on your images.
Now seriously hard to find; this is a superb lens and you will not easily find a better example – or any 55mm lenses at all come to that as everybody wants them. This is the very highly regarded and much improved N version. .