buzzer or beeper is an audio signaling device. Typical uses of buzzers and beepers include
alarm devices, timers and confirmation of user input such as a mouse click or key
Buzzer is an integrated structure of electronic transducers, DC power supply,
widely used in computers, printers, copiers, alarms, electronic toys, automotive
electronic equipment, telephones, timers and other electronic products for sound
devices. Active buzzer 5V Rated power can be directly connected to a continuous
sound, this section dedicated sensor expansion module and the board in
combination, can complete a simple circuit design, to “plug and play.”

 Input supply: 5 VDC
 Current consumption: 9.0 mA max.
 Oscillating frequency: 3.0 ±0.5 KHz
 Sound Pressure Level: 85dB min.