AMPHENOL T3110-000 C16-1 4 WAY (3+PE)  MALE SCREW RECEPTACLE  ECOMATE

This part has subsequently been replaced by 
C016 20C003 100 12
You can see the spec for that replacement part here https://uk.farnell.com/amphenol/c016-20c003-100-12/circular-conn-4pos-rcpt-panel/dp/3436484
 

New, old stock, military surplus - more money wasted! 
Some of the bags are slightly dirty, but not bad 

If you are wanting 10+ quantities drop me a message for better pricing