The MIDI Mongoose utilizes a standard 9V alkaline battery (not included). To install a battery:
1. Unscrew the 2 thumbscrews on the right side to remove the side panel.
2. Slide the bottom cover accordingly to access the battery clip and connect the battery.
3. Slide the bottom cover back into position, being careful to not pinch the connector wires.
4. Replace the side panel and thumbscrews.
The MIDI Mongoose is also phantom power operable via MIDI Cable, as well as 9V DC regulated or unregulated, 100mA minimum power supply with 2.1mm female plug, center negative(-). Optional factory power supply is available: Tech 21 Model #DC9.
For more info on the MIDI Mongoose, click here:
http://www.tech21nyc.com/products/effects/midimongoose.html
For full video demo of the MIDI Mongoose, click here:
https://youtu.be/uT9WVwMztJw