The Neutrik NL4MP is a 4 pole chassis connector, D-size flange, with countersunk thru holes, and screw termination. This chassis connector is not airtight.
 
4 Pin 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.
Current rating 30 A rms
Glass reinforced materials make it extremely robust and dependable
Precise keyway for secure mating
Accurate twist lock latching system
Metal insert in locking area
Airtight design - optimized for speaker applications
Branded with unique hologram - guarantees genuine and authentic Neutrik product