Features: 
With digital natural sound-effect technology, show perfect sound quality. 
Support MP3, WMA format files 
Built-in sound card, power and signal supplied by same USB cable. 
Support SD/MMC memory card and USB flash disk. 
Suitable for devices equipped with a 3.5mm audio jack, including cell phones, MP3 players, and laptop/desktop computers. 
Unique digital noise-lower technology.