Combined two functions of FM radio and earphone. Use earphone to listen to PSP Go game music and no need battery to support. It can also receive the broadcast.which the frequency range from 88MHZ to 108Mhz.the volume can be controllerd as well. When listening to the FM broadcast. It is not necessary to use PSP Go console and when pluging it into PSP Go console for game. The radio sound can be cut off and shift to game sound automatically. Connect the buckle respecitvely to thePSP Go and radio then the console can be hung on the chest conveniently. Just release the buckle to plya game.