What is this eyepiece?

What is the eyepiece on the left in this photo? (The center one is a 32mm Orion Sirius Plossl in a 2" adapter and the one on the right is a Surplus Shed 38mm erfle.) The mystery eyepiece is about 38mm fl and has a very wide ~65-70 degree FOV. Rather long eye relief, so it is a bit picky on eye position. There are no labels that I can see and as far as I can tell those diopter adjustments don't do anything (unless it is frozen with age). It came in a box of old astro equipment donated to the local middle school. I don't really know it's age. By the way, the views are great in it when you can get your eye positioned correctly.

Charlie

Attached Image:

The eyepiece pictured is likely a surplus military eyepiece sold in the 50's, 60's and 70's by Jaegers or several other companies. The 2" adapter for it is not original and could have been an add-on by surplus dealer or by an earlier owner of this eyepiece.

For years Jaegers sold a 38mm erfle which was also marketed as a kodachrome viewer as you could put it right on top of a 35 mm slide for viewing it. I have a 38mm Jaegers from 1978 but mine does not have the diopter adjustment.

Barry Simon

I've seen them...., I had one... Got it from a surplus store in West Lafayette, IN in about 1985. The salesman there told me it was off a tank gun sight WWII era. I never took mine apart but it performed like an erfle in my estimation. Great views as I remember. Wish I still had it. You don't want to sell that one do you? (LOL) Thanks, Tim