a wireless stereo headphone, adopting 2.4G RF technology,connet with PC,TV,iPhone etc ... product is a wireless stereo headphone, adopting 2.4G RF technology. RF frequency:2.4GHZ ISM BANDSupport system:Win2000,Win XP,Win Vista ... and convenientConnet with TV,iPhone etcMicrophone:Microphone size:6mmSensitivity:-52dbImpedance:≤2.2kΩFrequency response: 75HZ-16KHZSpeaker:Speaker diameter:40mmImpedance:32Ω ...