... indicatorAutomatic power off function(low voltage or no connection)Headset Spec.:Basic button function: Vol+,Vol,power switchFrequency ... distance and range:8m,360°System required:WindowsXP,WindowsVista,Windows7,Mac etc.Package including:Headset 1pcs,USB transmitter 1pcs, ... USB charging cable 1pcs,manual 1pcs 2.4GHz wireless digital audio stereo headset(black) ...