FirstIm not an expert on these so I may be wrong about my description or elements therein. However to the best of my research and knowledge of optics, I have described this item. This is either a slit lamp or microscope binocular adapter I can not verify which despite extensive attempts. Secondthis adapter was removed from an Olympus Zuiko 50/1.4 lens (which it is shown mounted to in some of the photos); it was previously mounted on the front 49mm threads. It will mount on nearly any lens with 49mm filter thread, but I believe is intended for use with normal focal lengths in the 40-60mm range for full field of view and lack of distortion and vignetting of the ocular image.
You can obviously mount to a lens of your discretion and while it has a 49mm male mount, that thread can be adapted for lenses with other filter thread diameters. These are approximate but I aimed for precision. Silver Sleeve OD diameter: 23.2mm. The intended use, as research suggests, is to allow the secure and centered mounting of nearly any camera, via the lens, to the binocular optic for photographing the eye during examination or the subject of microscopic examination. Further, the point-and-shoot cameras option becomes a toss-out if anything goes awry with the camera.This adapter, unlike other options, mounts a camera via the lens to the optics, and so allows for the use of a very wide range of camera bodies, so long as the lens mounted will accept the adapter (which are many, many lenses and camera options). The adapter does NOT function as a macro adapter for a lens and cannot be used outside of binocular optics. NO LENS OR CAMERA OR ANYTHING ELSE IS INCLUDED. ONLY THE ADAPTER IS INCLUDED.
The item "Mentor 10x HEP Slit Lamp Microscope Camera Photography Lens adapter 23.2mm" is in sale since Saturday, August 1, 2020. This item is in the category "Business & Industrial\Healthcare, Lab & Dental\Medical/Lab Equipment Attachments & Accessories\Microscope Parts & Accessories\Microscope Camera & Lens Adapters". The seller is "officialthistlemoto" and is located in Washington, Missouri. This item can be shipped to North, South, or Latin America, all countries in Europe, all countries in continental Asia, Australia.