KOSS 184408 QZPRO Active Noise Reduction Over-Ear Headphones 40 Hz to 20 kHz frequency response offers full range of deep bass and treble clarity; Soft vinyl closed ear cushions create tight seal around ears and reduce ambient noise; Active noise reduction technology eliminates unwanted low-frequenc..
KOSS 186818 Plug Classic Noise-Isolating Earbuds Dynamic element positioned just outside the ear ; Soft foam cushion eartip made of hydrophilic-formed urethane expands for a custom fit; Freq resp: 10Hz-20kHz; Imp: 16ohm ; Sensitivity: 112dB/mW; 4ft, straight, dual-entry cord; Includes 4 extra eartip..