• 4 Midi inputs and 4 Midi outputs (64 Midi channels)
• Perfect Midi timing
• Midi merge function for mixing data of the inputs 1 and 2
• high-speed connection to USB-equipped Pc or Macintosh computers
• USB-powered; required no external power supply
• compact size
•  compatible with Windows XP, Vista and Mac OSX or better
• true plug-n-play, users do not need to install driver for Windows XP, Vista and Mac OSX

More info: MIDI 4i4o