... chips,good battery *radio MP3 player *mp3 player with built in speaker Mp3 player with built in speakerspeaker mp3,fm radio mp3 player, mp3 music player2G,4G,8G,16G ... and preservation of ACT and WAV format audio files; 4,or may choose to repeat fragment repetition contrast, the ... ,pls don't more than 4 hours.Otherwise it will extremely easily caused the built-in lithium battery failure and damage. ...