Pair of Nikon C-20X SMZ Widefield Stereo Microscope Eyepieces. The Nikon number is MMK30200 with a list price of $223.00 each. They will fit all of the Nikon SMZ series of microscopes except the Nikon SMZ-U. These are new still in original packing with a 30mm diameter and a FOV of 12.5mm. Each eyepiece has a diopter adjustment that functions smoothly as intended.  Sold only as a pair.