This buzzer module is passive because it has no internal electronics to generate a sound or a tone. External electronics or a microcontroller device, such as an Arduino, is required for the device to produce sound. Because the device is passive, it is more of a tiny speaker than a ringtone. Voltage: 3.3 - 5V Voltage: 3.3 - 5V With fixed bolt hole: 3mm for easy installation The module adopts transistor control 9012 No source of oscillation, need a square wave (frequency 2K-5K) to control Control you can create a “do re mi fa sol la si” effect
