Sony MDRZX110NC Noise Cancelling Headphones Over-ear, Noise-isolating Headphones. Connectivity Technology: Wired 30mm Neodymium Driver. 110 dB/mW  Power off, 115 dB/mW  Power on Up To 80 Hours Of Battery Life Frequency response:10-22,000 Hz Impedance (Ohm)- Power ON 220 ohm, OFF 45 ohm (at 1 kHz)