Neutrik NL4MPXX

4 pole chassis connector, black D-size flange, countersunk thru holes, 3/16" flat tabs.
 
The speakON panel mount connectors are the standard chassis connectors for loudspeaker / amplifier interconnections. They feature a unique metal locking system, making contact only once fully locked. The speakON receptacles are robust, versatile and easy to terminate.