Headphone Section: Speaker Dimension: ф30mm Impedance: 32Ω Sensitivity: 103dB s.p.l at 1KHz Frequency Response: 20Hz-20,000Hz Rated Power: 15mW Power Capability: 150mW Cable Length: Approx.2.5m Plug Type: ф3.5mmStero Microphone Section: Microphone Unit: 6*5mmDia.Electret condenser Microphone Directivity: Omni Direction Sensitivity: -58dB?dB Impedance: Low Frequency Response: 30Hz to 16,000Hz Standard Operating Voltage: 3V