PC, smartphone and tablet headset: Easy to connect and switch between devices Rich digital stereo sound: Laser-tuned speaker drivers, built-in equalizer and noise-cancelling mic for crystal clear calls and music*. Sensitivity (microphone)- -47dBV/Pa +/- 3dB. Sensitivity (headphone)- 97dB +/-3dB 40 ft. wireless range: Listen and chat up to 12 m from your PC-or pair with your smartphone or tablet using Bluetooth. Input impedance: 32 Ohms