Wireless stereo headset with 2,4 GHz technology for wireless enjoyment of music and telephone use through the Internet. Large, softly padded headphones, for optimal comfort wear. integrated microphone. Automatic pairing. Operating systems: Requires 2 AAA batteries. (Not included in delivery.) - Frequency response: 20Hz - 15kHz - Sensitivity: 85dB - Impedance: 32? - Driver: 30mm - Working distance: 50m - Plug and Play - Operating systems: Windows 2000, XP, Vista, Win7 and Mac OS