2 inch 41mm Military RKE Telescope Eyepiece proto-type

Description

This is a military 41mm eyepiece module that was used in targeting systems that the military no longer uses.  I purchased a batch of military surplus lenses and got some of these 41mm RKE modules as part of the deal.
The RKE design is a 3-element eyepiece that is commonly used in spotting scopes, rifle scopes , and other targeting systems within the military so you know the quality of the lenses is good. The RKE design does seem to work best in slower scopes from f/7 to f/15 , but they can also be used in slower f/ratio scopes.  The 3 element design is a simple one and does not have the additional elements for edge correction in faster scopes that a Plossl or Konig design with 4~6 elements .
A lot of astronomers do like the fact that there is a higher light transmission and brighter images with fewer lenses, especially in smaller diameter scopes that don't bring in as much light.
This would make a great Star Party eyepiece, or simply a good eyepiece to get your 2 inch collection started for the person on a budget.
Only one available ..might be more in the future though.... The Perfect Gift for any Astronomer.
18mm eye relief and is threaded for standard 2 inch filters.
S&H in the 48 states is .88 for US Mail. Outlying areas .50.
I ship ONLY within the USA, No foreign bids , PLEASE !!
Paypal payments are preferred ,  Ebay only allows that sellers advertise Paypal, so if you need other options please contact me through the red & blue "ME" link next to our feedback .