... , tf card slot to read FM radio, MP3 player,Amplifier Portable Waistband Mini Amplifier with USB/SD FM remote control ... hoursRechargerDC3.7VBattery working timeKeep working in 7-8 hoursFunctionMp3, FM radio, Amplifier, Line-in, loudspeaker, microphone, reverberationColor ChoiceBlack with ... : 1 pcWaistband : 1 pcSpecification : 1 pc Portable Waistband Mini Amplifier with USB/SD FM remote control