Gear Head AU7000W. Device connectivity: Wireless, Device interface: USB. Ear coupling: supraaural, Headphone frequency: 20 - 20000 Hz. Microphone frequency: 100 - 15000 Hz, Microphone sensitivity: 54 dB. Battery life (max): 5 h, Standby time: 2160 h, Charging time: 3 h. Windows operating systems supported: Windows 2000, Windows XP, Windows Vista, Windows 7, Mac operating systems supported: Mac OS X 10.4 Tiger, Mac OS X 10.5 Leopard, Mac OS X 10.6 Snow Leopard, Mac OS X 10.7 Lion