Full Details from Amazon.com : http://www.amazon.com/gp/product/B002PAQY76?tag=onigi-20

Macally TUNEFAN 2.1 Stereo Speakers with Subwoofer and Cooling Fan

USB powered speakers and cooling fan
ACDC adapter included to boost the audio performance
Line-in jack to support other audio or MP3 players
Ultimate thermal solution to cool down your notebook
OnOff switch for cooling fan and amplifier