Hi Folks,
No they're not some strange pair of binos, although you could try if you have very wide set eyes. I just acquired the 2nd of these 2 lenses. They are a pair of Nikon 400mm f2.8 lenses for my take on the dragonfly array thing (x2 for now), -
"Bumble Bee" 
. for a 400mm f2 ... (equivalent exposure) or 600mm f2.8 equiv. or 800mm f4 equiv. with 1.5x and 2x Teleconverters resp. (Need to test the Image Quality and acquire some more Nikon TCs before going crazy on that (the TC) route).
I now need to find time to make a fixture to hold both lenses on a mount whilst also (possibly/probably) providing a means of optical alignment. I need to rope in my brother for some of his wonderful welding work (Hi Den)
Best
JA