16 MIDI input channels and 16 MIDI output channels LEDs indicate power in, MIDI in the signal and MIDI signal out USB bus; Does not require external power Supports Windows XP, Windows 7 Cable length: 2.0 m (6 ft) How to use: 1. Connect the "up" to the MIDI "OUT" of a MIDI keyboard Cable (or MIDI device). 2. Connect the "OUT" to the MIDI "IN" socket of a MIDI keyboard Cable (Of MIDI device). 3. Plug the USB cable into a free USB port on the computer, The red LED is lit to show the power supply. 4. Open up your music software , such as , Sonar, MIDI connections, 5. Set the music to MIDI in And MIDI-out devices "USB Audio Device" 6.Your USB MIDI interface is now for use. Material:plastic Color: as shown Included: 1 x USB electronic music Use the registration matters: USB has not been successfully , you need to change the interface to drive or download the driver to drive the computer's USB drive Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.