385 Audio Edge Over-Ear Stereo Headphones with Microphone (Black) Driver Diameter: 40mm Frequency Response: 20-20,000Hz Microphone Sensitivity -58dB plus 2dB Impedance: 32ohms plus 15% Microphone Operating Voltage 4.5V Sensitivity: 115dB plus 03dbMicrophone Impedance: 2.2K Max. input power: 50mw Cable length: 1.5m