BUILT-IN STORAGE: PEMENOL voice module features 64Mbit (8M bytes) of internal storage and can be connected to a computer via the included USB cable for audio file replacement. Note that a USB cable should be used instead of a charging cable, as the latter may not allow the computer to read the audio files..TWO INDICATOR LIGHTS: PEMENOL voice module is equipped with two indicator lights that show the status of power supply and playback. This feature is very helpful for users to monitor the working status of the voice module and operate it conveniently..9 WAY TRIGGER PORT: PEMENOL voice playback module is designed with 9 way high pressure and high temperature resistant trigger ports. Without programming, you can directly connect the trigger button to realize a variety of playing modes, such as single cycle, sequential play, etc..WARNING DEVICE: PEMENOL Voice Broadcast Device can be connected with external buzzer or light alarm. It can be used as the alarm device for families, supermarkets and warehouses. You can freely change the alarm effect or sound you want..VOLUME ADJUSTMENT UPPER LIMIT: PEMENOL MP3 Music Player can not only adjust the volume with the button, but also set the upper limit of adjustable volume by adjusting the potentiometer.