1,Necklace MP3 Music Player 2,color prin ad/logo/photo on the two sides 3,usb2.0 high speed 4,Rechargeable Li-ion Battery Necklace MP3 Music Player Necklace MP3 Player,Supports MP3/WMA formatUSB 2.0 high speed, No display,Li-BatteryNo drive installation required System RequirementsHardwarePC, Notebook or Macintosh with USB port Function CharacteristicsUSB InterfaceUSB2.0 high speedCapacity128M, ...