mini Speaker 1).USB power supply 2).with volume control 3).convenient for carry 4).excellent tone quality mini SpeakerMain function and features:1).USB power supply2).can work with any player with a 3.5mm audio output jack, i.e. Ipod, laptop, MP3, MP4, CD, PC3). plug and play4).with volume control5).bass, treble stereo speaker6).compact design7).portable, convenient for carry8).excellent tone ...