This item is a Nikon Series E 100mm f/2.8 Telephoto Prime Lens.  It is in great condition except that there is a smear (?) of some kind behind the rear element.  It looks like it was serviced and the rear element wasn't cleaned properly afterward.  I am pretty sure it is not fungus or haze.    It looks great cosmetically, otherwise.  The aperture blades are clean and work fine.  The focus is smooth.  I am selling it AS IS, no returns.

The front element is fine.  I forgot to remove the UV filter.  I redo the pictures as soon as I  can.