Feature: 1. 4 MIDI inputs and 4 MIDI outputs (64 MIDI channels). 2. Merge function 2 ins-\u003e 4 outs included. 3. Perfect MIDI timing. 4. High-speed connection to USB-equipped PC or computers. 5. USB-powered, required no external power supply. Specification: This MIDI conversion device is the best companion for music editors to connect multiple MIDI devices for music creation. Features: 4 MIDI inputs and 4 MIDI outputs (64 MIDI channels). Merge function 2 ins-> 4 outs included. Perfect MIDI timing. High-speed connection to USB-equipped PC or computers. USB-powered, required no external power supply. Mini compact portable size. Can switch among USB mode and 4 Through modes. Compatible with Wins XP, Vista, 7 and Mac OSX or better. True plug-n-play, you do not need to install driver for Wins XP, Vista, 7 and Mac OSX. Specifications: Material: Metal Item Size: 146.5 * 83.5 * 40mm / 5.77 * 3.29 * 1.57in Item Weight: 303g / 10.69oz Package Weight: 466g / 16.44oz Package Size: 20.5 * 17.5 * 6.5cm / 8.07 * 6.89 * 2.56in Package List: 1 * MIDI Box 1 * Cable 1 * Manual (English) Package List: 1 * MIDI Box 1 * Cable 1 * Manual (English)