amplifier module--mp3 player board 1.mp3 player board with MCU control 2.bulit-in amplifiler mp3 ... board 3.stable performance amplifier module--mp3 player boardFeature 1. control by MCU or pushbuttons 2.play mp3 ... Graden , banks , schools , hosplitals , etc .mp3 module,mp3 player , embedded audio module , serial mp3 module amplifier module--mp3 player board,driver amplifier module