I was just curious what is the difference between PVS7A's, PVS7B's, PVS7C's and PVS7D's?
I always see the different models but was never sure the little differences?
I never actually saw any Charlies.
The Deltas also have accesories that you can attach. I don't think the magnifier or the compass fit on any of the earlier ones.
ETA: I looked around and couldn't find any tables comparing the tubes, so I don't know if the difference is in resolution or what. But I was issued Alphas, Bravos, and Deltas and there was a definite improvement in range and clarity with each new model.