High Performance Noise Cancelling Stereo Headphones with built in battery

1) Speaker: ø40mm
2) Magnet type: Neodymium
3)Impedance : 32Ω±10%
4)Frequency response : 20Hz - 20KHz
5)Plug: 3. 5mm stereo plug
6) Speaker sensitivity: 105±3dB/mW@1kHz
7) THD: <1% @94dB, 1kHz
8) Rating/maximum power: 20mW/30mW
9) Power requirement: 2 × AAA batteries