1) Speaker: 30mm Ferrite 2) Frequency range: 20-20KHz 3) Impedance:300ohms ?0ohms at 1KHz 4) Sensitivity:105dB/mW?3dB(at 1KHz) 5) Rated & Max. power output:40mW&100mW 6) Plug type: Nickel-plated 3.5mm dual plug 7) Cord length: 1.2m single wire 8) Adjustment of earcups: 90oC Swivel