2 pole chassis connector, black D-size flange, self tapping screw holes (A-screw), horizontal PCB mount. Does not intermate with the 4-pole cable connector. 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.