Sennheiser PC 121. Device connectivity: Wired, Cable length: 3 m. Headphone frequency: 50 - 15000 Hz, Impedance: 32 Ом, Headphone sensitivity: 114 dB. Microphone frequency: 80 - 15000 Hz, Microphone sensitivity: -38 dB, Microphone input impedance: 2000 Ом