Denon Dual DJ MP3 Player Shock Resistant Mounting Protection Extremely rugged construction for long life even under the harshest and most demanding conditions External USB Device Support (You can hook up a portable hard drive, or thumb drive, or Ipod, or other USB device) Next Track Function through Cross Fader (This is the first time we have seen this thoughtful feature) Seamless Loop A & B data can be stored directly to the track