... are optional System: Google Android OS 2.2 Basic configuration: stereo head set ,charger,USB line, size: 198*118*12. ... Electronic compass Music Frequency: CODEC+Class DX2 Speaker: built-in stereo spearker, Audio format: MP3/WMA/AAC/AAC+/eAAC+/AMR/ ... Skype, QQ, etc.), network tools bluetooth: call, file transfer, bluetooth stereo headsets Business:Office, word/excel/PPT file format document read, editor ...