mystery Adjustable focus Ocular Eyepiece for 28mm OD tube w/ cross reticle

Description

exact item shown, not sure what it fits, it has a cross-hair type reticle in the lens, adjustable focus, the connecting tube at the bottom fits over a 28mm dia tube.  if you happen to recognize this, please let me know so I can update the listing and get it to someone who can use it.  I've had this for a bunch of years and haven't figured out what it fits.
Note to me: second thin drawer
I normally ship within 24 hours of your order, but the post office does not always initiate tracking when I put the packages in the drop off box.
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