This is a small 12mm round passive buzzer that operates around the audible 2kHz range. We drove it directly from a 3v to 5V Arduino or micro:bit to generate simple melody.
Note: This passive buzzer requires a square wave (PWM) signal to make a sound or to play melodies. The frequency of this PWM signal will determine the tone. Supplying just a fixed voltage will generate no sound, except perhaps a slight "tick" at the point when the power source is connected or disconnected from the buzzer.