[Milsurplus] connector ID

[Joseph Orgnero]

Hello all,
Tidying up my shack I found some RF connectors that I cannot identify. They
are marked "83870-UG-495D/U". They look like oversize N connectors, .75" in
diameter, with a 1" opening at the back for the cable (hardline?).
Does anybody knows about them?. Like, what series they belong to, what
connector they mate with, where were they used, etc.
I have four brand new ones and if anybody can use them please contact me (I
don't know what are they worth).
Thanks for any info.
Joe Orgnero VE7LBI  CCA 96-418