The SD205 is a stereo direct box that hasbeen specifically designed to interface a laptop, tablet, smart phone or musicplayer with professional audio system. It comes with a 3.5mm connector cable,the detachable cable for easy storage. The transformers also eliminate lowfrequency noise. Using the SD205 improves the sound quality by properlymatching the impedance and optimizing the signal level. SD205 also does notrequire any power which is passive stereo DI box, just plug and play.