... with USB/SD FM remote control with usb, tf card slot to read FM radio, MP3 player,Amplifier Portable Waistband ... Mini Amplifier with USB/SD FM remote control Item No.: GSG ... hoursRechargerDC3.7VBattery working timeKeep working in 7-8 hoursFunctionMp3, FM radio, Amplifier, Line-in, loudspeaker, microphone, reverberationColor ChoiceBlack with ...