Unused in mint condition in the original military packaging. Complete prism cluster (right side) for your Mark 28 7x50 binocular and fits many others! Well made mounted two prism erecting assembly is what you need for building a spotting scope or monocular. Two mounted porro prisms, 2 inches long by 1 inch high. Assembly is 2-1/2 inches thick by 2-1/2 inches diameter and the view openings are 1 inch diameter. Coated optics, unused!