midiplus miniEngine USB MIDI Sound Module USB host USB MIDI sound module MAXIMUM POLYPHONY: 64 notes INSTRUMENTS: 128 GM List Sound DISPLAY: 3 Digital LED JACK: Headphone(LINE) OUT, MIDI IN, USB host, Micro-USB POWER SOURCE: Micro-USB(500mA) BATTERY CAPACITY: 2500mAh INPUT/OUTPUT HEADPHONE(LINE)OUT: 3.5mm stereo headphone jack MIDI IN: MIDI input jack USB HOST: USB output jack (to MIDI equipment) Micro-USB: Charging/power jack ATTACHMENT: Owner's manual, 3.5mm TS to MIDI cable, Micro-USB cable is unique design which works as USB host that you can connect USB MIDI keyboard directly to mini Engine to get sound no need to connect to our computer.