Sony DR-270DP Stereo Headset. Headset type: Binaural, Colour of product: Black. Device connectivity: Wired, Cable length: 1.2m. Headphone frequency: 14 - 22000 Hz, Impedance: 24Ω, Headphone sensitivity: 100 dB. Microphone frequency: 20 - 20000 Hz, Microphone sensitivity: -35 dB, Microphone input impedance: 1000Ω