Eskuche 33 1/3 MAT BSide Classic Style Headphoines - unique interchangeable cord system: 1 cord for audio only (3.5mm with 1/4" adaptor), 1 cord for use with mobile devices (cord includes in-line answer/end button and mic for iphone and most Black Berries) - 40mm drivers - 32 - 20% impedance - frequency response: 20Hz - 20KHz - sensitivity: 112dB