Sennheiser PC 36 USB. Device connectivity: Wired, Cable length: 3 m. Headphone frequency: 40 - 18000 Hz, Impedance: 32 Ом, Headphone sensitivity: 109 dB. Microphone frequency: 80 - 15000 Hz, Microphone sensitivity: -38 dB, Microphone input impedance: 2 Ом. Compatible operating systems: Win 98 SE + Mac OS 10.3.9 +