1.Frequency Range 32?5%Ω at 1kHz 2.Impedance 300～3400Hz 3.Sensitivity 110?dB at 1kHz, 179mV, IEC318ear 4.Rated/Max Power 5mW/10mW 5.T. H .D. Less than 5% at 1kHz, 5mW 6.Weight Approx 1.2 gram