[toni-a]

Usually in microscopes you don't look at objects like with macro lenses, the subject is retro illuminated and you actually see through.
Always microscopes come with an adjustable support for your subject, for focusing you move your subject, there's no focus ring on the microscope lens, focus ring is on the base and it just moves the subject.
My wild guess what you have would be part of the base where you put the subject, most likely it's a lighting device, does it contain optical fibers or electric cables ?? Does the round base contain any lamps ??? I think you bought just the optical part of a microscope ?