The d.2 is the world's first mixer with an optional FireWire computer connection. With the FireWire card installed, you can connect the d.2 mixer to any Mac or PC (Mac OSX 10.3.5 and higher, Windows XP) to directly play back music from almost any music software application—including Traktor, Serato, Live, iTunes, and Windows Media Player. You just set the Input Select switch at the top of either or both channels to "FireWire," and mix two stereo tracks directly from your computer.