Used (barely) M Audio Torq MP3 mixer. This unit connect to your computer and allows you to play and mix 2 MP3's at a time, enabling you to play gapless party mixes and keep the music flowing. The software includes a program that even sync's the two songs together for you for seamless play. I used this mixer only a few times then my computer broke. It's a "B" unit which means it had some cosmetic flaw, but still looks and works just like new. Thanks for looking and good luck bidding.