Portable mp3 player sports mp3 player internal memory 4 gb memory expansion microsd audio formats mp3 wma aac ogg flac audible wav display size 144 inch display diagonal 366 cm display resolution 128 x 128 pixels display types lcd tft battery life audio 25 h power supplies internal battery charge via usb connections micro usb microsd slot functions upgradeable firmware radio organiser folder navigation battery charging indication id3 tag col