... radio,built-in Lin-ion 4.USB cable Features: This wireless speaker can link to MP3, MP4, Notebook, CD, DVD, Mobile ... playing by plug in straightly. 1)Support SD/USB/SMM card, Auto play function2)with Aux-in connection, support: MP3/MP4 ... : built-in Lithium rechargeable battery & USB power supply (5V, DC) wireless speaker