AKG K92 | Over Ear Closed Back Monitoring Headphone Precisely balanced response provides reference-monitor accuracy Professional 40mm drivers for extended 16Hz - 20kHz frequency response Over-ear design and lightweight construction for exceptional comfort Closed-back design maximizes isolation 3.5mm (1/8 inch) gold-plated plug with gold-plated 6.3mm (1/4 inch) screw-on adapter