[TowerTalk] What's this connector called?

[Kevin Zembower]

Hello,

My club uses a connector that I'm not familiar with. It's like an N-type 
connector, but uses a bayonet outer shell, like a BNC connector. I've 
posted some pictures at 
https://www.dropbox.com/sh/rxve1baqohdyb74/AAAVMTdUuikeNz06oT2wTxLOa?dl=0

Can anyone tell me what this connector is called, so I can look them up? 
Is it a rare connector? I was told that it's a military standard. Are 
they still available? From who, if it's rare?

Thanks in advance for your help.

-Kevin
KC3KZ