The M-Audio USB Uno 1X1 MIDI Interface is a complete USB-to-MIDI solution, equipped with a USB connection to your computer and a 1-in/1-out 16-channel MIDI connection to your MIDI devices. Tiny unit comes with USB and MIDI extension cables, features MIDI activity indicators, and works for Windows or Mac. Single MIDI in and out connectors make it perfect for connecting a keyboard or controller to your computer quickly and easily. Powered by the USB port. USB supports connection of up to 127 devices simultaneously, any of which may be hot-plugged from the USB bus at any time. Requirements: Windows 98 SE, 2000, ME, or XP; Mac OS X 10.1.5 or greater.