2 pole chassis connector, black D-size flange, countersunk thruholes, 3/16″ flat tabs. Does not intermate with the 4-pole cable connector. 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.