sport mp3 player 1.Without built-in memory 2.Support Micro SD/TF card 3.Built-in polymer Lithium battery 4.Can use 5 hours Best-selling sport mp3 player with good quality Detailed description Smile face MP3 with clip Supports audio formats,such as MP3,WMA, and WAV With built-in polymer Lithium battery Accessory:Gift box,Earphone,usb cable,user manual System requirementsHardwarePC or notebook has ...