Voice Playback Module MP3 Player UART I/O Trigger Amplifier Class D 5W 8M Storage DY-SV8F Flash SD/TF Card - Walmart.com
Improving the Sparkfun MP3 Trigger – Zach Poff
Amazon.com: SparkFun MP3 Trigger - 18 Trigger inputs to Alternate Functions Random & sequential Track Selection Transport Controls Even Volume up/Down Real-Time Volume Control Full-Duplex Serial Control : Electronics