Logitech H150 Stereo

Output Impedance: 22 Ohms
Sensitivity (headphone): 122 dB +/-3 dB
Sensitivity (microphone): -44 dBV/Pa +/- 2.5 dB
Frequency response (Headset): 20Hz-20KHz
Frequency response (Microphone): 100Hz-6.5KHz