This is the rare LWD model with. Aperture, similar to a fluorite lens. As opposed to the more common.
ELWD model with lower 0.80 NA. For vertical / reflected incident illumination. Or coverslips, and for macro. Intended for Nikon Optistations with M26 BD threads. And 210 TL correction, also usable in other scopes.
From Olympus, Zeiss, Leica with similar M26. _gsrx_vers_1233 GS 8.1.1 (1233). The item "Nikon BD Plan 100x LWD /0.90 Long Working Distance 210 TL Microscope Objective" is in sale since Tuesday, August 11, 2020. This item is in the category "Business & Industrial\Healthcare, Lab & Dental\Medical/Lab Equipment Attachments & Accessories\Microscope Parts & Accessories\Microscope Objectives". The seller is "josedm1" and is located in Yakima, Washington. This item can be shipped worldwide.