These are ITT / Cannon
XLR-4-12C Four Pin Male Plug Connector ( XLR412C )
with Gold Terminals
accommodates 16 gauge wire 
Factory kitted with a necessary hardware

These 4 pin XLR connectors are used in Guardian Buddy Phone underwater diver communications systems and firefighter wired headset communications

These are factory new parts. They have never been installed and have not been recovered from manufactured electronic components.

These terminators and RF connectors were store stock inside of Luddite Electronics when located in downtown Longmont Colorado. This bricks & mortar store closed in 2015.