Midiplus Mini Engine Usb Midi Sound Module General Midi Built-in 2500mah Rechargeable Lithium Battery Provides 128 standard GM tones, up to 64 polyphony output. 16 bit sampling accuracy of the data, 48kHz sampling frequency, 24dB sound digital filtering. Data rotary knob to adjust Volume, Program, Reverb effects. LED shows the value of the current volume, program, reverb. Support all the MIDI devices that have MIDI output or USB output. Either MIDI or USB connection can be manifested no delay. Support MIDI IN and USB HOST working simultaneously. Built-in 2500mAh rechargeable lithium battery can power your MIDI devices. 3.5mm headphone output interface: Connect headphones or other output devices. Maximum polyphony: 64 Tone: 128 standard GM Power source: Micro-USB Item size: 10.5 x 7.5 x 2cm / 4.1 x 3 x 0.8in Item weight: 188g / 6.7oz Colour: blue Material: aluminum alloy Package Contents: 1 * MIDI sound source 1 * 3.5 to MIDI cable 1 * USB cable 1 * Chinese and 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.