It contains the following:
• Arduino-compatible microcontroller
• MP3 (and many other formats) audio decoder chip
• micro-SD card socket
• Stereo audio amplifier
It’s such a recommended product to get, especially that it gives your fabric creations any sound of your choice.
It can be powered using either of these two sources which are:
• 3.7V Lipo battery (charger built-in!)
• external 3.5-6V source
In addition to that, this board plays play specific audio files when any of its five trigger inputs are grounded when it off the shelf, however, RGB rotary encoder(not included) can be soldered in and load new firmware (included in the link below) which is controlled by the user.