Panasonic Wired Earphones - Wired , Purple (RP-HJE125-V) Drive Unit (diam. in mm) 9.0 Impedance (Ohm) / 1 kHz 16.0 Sensitivity (dB / mW) 97.0 Max Input (mW) 200.0 Frequency Response (Hz - kHz) (en JP) 10Hz - 24kHz