M-Audio MIDISPORT 2x2 Anniversary Edition | 2-in/2-out MIDI Interface (32x32 discrete channels I/O via USB) 2-in/2-out MIDI interface: 32 discrete MIDI input channels, 32 discrete MIDI output channels Compact and lightweight for mobile or desktop use Connection and power via USB, requires no external power supply Standalone functionality with MIDI merge and 'passive' THRU mode MIDI activity LED indicators for each port