Neutrik SpeakON 4-Pole Loudspeaker Connectors - Neutrik NL4MPXX, The Neutrik NL4MPXX is a 4 pole chassis connector with a black D-size flange, countersunk through holes and 3/16in. flat tabs for connections.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. Neutrik NL4MPXX Speakon L/Speaker Socket