Frequency Response: 20Hz-20KHz Speaker: 40mm, Impedance: 32 3dB,1KHz Rated Power: 25mW(Maximum:50mW) Microphone: 6X5-58 4dB Connector Plugs: 3.5mm, Stereo Special Function: 70% antinoise effect,undisturbed imagination Antinoise amplitude: -15dB 3dB