Zeiss DIC Microscope Slider Prism for the  40X/ 1.30 oil Plan Neofluar objective. It is intended to be used on the transmitted line of clinical infinity corrected microscopes. It is housed in a black plastic storage sleeve and has t he following dimensions: 46.95mm in length, 15mm in width and 3.5mm thick.  This item is new, however not in original factory packing. The Zeiss product number is 44-44-57 and is in their current product listings.