It has 4 lenses in total, two at each end. The only text on it is the number 50, stamped into the bottom of the ring that goes around the outside to attach it to whatever it goes with
It has 4 lenses in total, two at each end. The only text on it is the number 50, stamped into the bottom of the ring that goes around the outside to attach it to whatever it goes with
I’d guess some kind of vintage microscope 50mm eyepiece. Maybe telescope