Plantronics' DSP-400 is digitally enhanced with a Digital Signal Processor, foldable stereo headset with full-range digitally enhanced stereo sound. The foldable design allows for easy storage and transport. Listen to your CDs, DVDs, or MP3s. The noise-canceling QuickAdjust microphone boom allows the user to position the microphone easily and consistently for uniform performance and higher, enhanced accuracy. New lightweight materials are used for ultimate comfort. It is packaged with Plantronics' PerSono Audio Control Center Software and as a bonus includes leading speech and voice recognition applications and a robust MP3 player.