Zeiss Plan Achromat 100X oil immersion microscope objective that fits the Zeiss Standard, Universal, Photomic and Ultraphot microscopes.  It will also work with other 160mm TL microscopes from Leitz, Olympus, Nikon and others.  This objective has an N.A. of 1.25 and does not require the use of a coverslip.  It is in nice optical, cosmetic and mechanical condition however the case shows some signs of wear.  There are no element separations or oil migration into interior elements.  All of the glass surfaces are free from fungus, dust, and scratches.