3 in 1 Function, combined with USB MIDI, Merge and thru functions. 4 Inputs, 4 Outputs MIDI interface (64 MIDI Channels).MIDI Merge Function for mixing data of the inputs1 and 2, 4 output.Perfect MIDI timing, USB powered (no external power supply requires).High-speed connection to USB equipped PC or Mac computers.True Plug and Play & Wide compatible, users do not need to install drivers. Mode SW: USB and MIDI THRU mode switch button.This button lets you choose one of the 5 operating modes of the interface ( One USB mode and 4 MIDI Thru modes)With this MIDI Box, you can obtain perfect midi timing and performance at an extremely affordable price.Compatible with Windows XP, Vista and Mac OSX or betterMIDI in and MIDI out activity indicators for each port USB powered (no external power supply requires)Material:metalcolour:black Package Contents:1 x MIDI box1 x cable1 x English manual Only the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.