... ,Yahoo Messenger4.USB wireless transmitter dongle, plug,play,easy to use5.Simple set up,no software driver installation is required6 ... Wired)7.Rechargeable battery by USB cable,up to 5 hours continuous usage8.Fully media player functions:next.previous,vol+/-,play/pause. You ... THD+N(0dB@1kHz):-50dBbattery : Rechargeable battery by USB cable,up to 5 hours continuous usage hopping RF-channels:2402~2481 ...