... 1,Rechargable Li-battery 2,Headset micrphone 3,USB/TF card ,FM Radio 4,Mini size ... .m*Reverb/Echo function*MP3 by TF Card, USB flash disk supported, FM Radio Function*Built-in ... Lithium Battery, convenient and environmental*Connect computer with USB data link, used as speaker*Built-in 3" ... Speech,Publication,Outdoor entertainment 2012 Belt Portable Mini Audio Amplifier Speaker with Reverb/Echo V-3