Carl Zeiss 40X plan achromat microscope objective. The Zeiss catalog number is 46-07-10-9904 with a last list price of $760.00. It has a working distance of 0.7 mm,  n.a. of 0.65, and focal length of 4.13mm.  All glass surfaces are free from element separations, dust, scratches, and fungus. This objective is intended to be used on 160mm tube length Zeiss microscopes such as the Standard, Universal, IM and Photomic. It will work equally as well on microscopes with this 160mm TL from Leitz, Nikon and Olympus. THE SALE IS FOR ONE EACH OBJECTIVE. Thank You For Looking