Amazon.com: 3PCS Mini MP3 Player Audio Module MP3 Voice Decode Board TF Card U Disk IO/Serial Port/AD Board DFPlayer Audio Voice Music Module for Arduino : Electronics
How to use the DFMini Player MP3 Module with Arduino - DFRobot
DFPlayer Mini Mp3 Player - DFRobot Wiki
MP3 player using Arduino and DFPlayer mini - Electronics-Lab.com