Type: Stereo headphone Speaker: 40 mm NdFeB speaker Impedance: 40Ω±15% Sensitivity: 113±3dB @1KHz 1mv Rated Input power: 10mW Max. Input power: 30mW Sensitivity: -40dB±3dB@1kHz (0dB=1V/pa) Output impedance: Max: 2.2KΩ (@1kHz) Frequency: 100Hz~10KHz Standard operation voltage: 2V