Logitech H540 USB Headphone With Noise Cancelling Mic

Microphone Type: Bi-directional

Input Impedance: 20 Ohms

Sensitivity (headphone): 115 dB +/-3 dB

Sensitivity (microphone): -42 dBV/Pa +/- 3 dB

Frequency response (Headset): 20 Hz - 20 KHz

Frequency response (Microphone): 100 Hz - 16 KHz