1,Foldable 2, Bluetooth 2.1 wireless 3, High quality Products descriptionBluetooth wireless headsetSupport systems:audio equipments with bluetooth functions, ... :20Hz—20KHz;S/N ratio:_82db;Charger power:computer USB interface DC5V;DC5V(500MA);travel charger;DC 5V ... Response:30Hz-16.000HzOperating voltage:3.0v Wireless stereo bluetooth headphone foldable new style for computer, PC, Ipad, Ipod, Xbox etc ...