2 pole chassis connector, black D-size flange, countersunk thruholes, 3/16" flat tabs. Does not intermate with the 4-pole cableconnector. The speakON panel mount connector is the standard chassis connector for loudspeaker/amplifier interconnections. It feature a unique metal locking system, making contact only once fully locked. The speakON receptacle is robust, versatile and easy to terminate.