Active noise cancelling headphone Noise reduction level:5db-13db at 30-600hz Frequency: 20hz - 20khz Impedance: 320¬+f+20% at 1khz Sensitivity: 122dbf+3db at iec-318 1khz 1mw(0db=0.00002pa) Power supply: 1.5v Speaker: 36mm Rated power:20mw Max. Input power: 30mw Cable length: 1.5m Microphone: ¬+6*1.5(-60db) Plug: 3.5 stereo plate golden Supply voltage: dc1.5v 1*aaa battery Working time: 20 hours
