This voice modules is a kind of simple MP3 player device whose design is based on a high-quality MP3 audio chip - WT5001. It support 8KHZ~44.1kHZ sampling frequency MP3 and WAV file formats. There is also a Mini SD card slot to store the music files. You can control the MP3 playback state by sending commands to module via serial port tools or pressing buttons, such as switch songs, change the volume and play mode and so on. It seems a simple module, but it owns such strong function and have a relative high quality.