Nextar MA9682 - 256MB Wireless MP3 Headphones Music Format Compatibility - MP1/MPMP2/MP3/WMA/WAV/ASF/WMV Port Mode - USB 2.0 Protocol. (FS) EQ Mode - POP, Classic, Soft, Jazz, Dbb, Rock, Normal Playing time - Can continuously play music for about 350-400 minutes after fully charged Battery Voltage - 3.7V Rechargeable Li-Ion Battery.