Type: Back-hook headset Item No.:M501MV Features: 1) Frequency Response: 50 Hz-20kHz 2) Speaker Impedance: 32 3) Driver Unit: 30mm 4) Rated Power: 15mW 5) Power Handling Capability: 20mW 6) Cable Length: 2.3M 7) Sensitivity:110+/-3dB 8) Microphone: 6?mm-58dB+/- 2dB 9) Plug: 3.5mm, Microphone in Red, Earphone in Black