The Buzzer is an acoustic signaling device that is electrically operated. The construction of the electromechanical buzzer is devoid of a hammer and a metal basket, resulting in a buzzing sound (hence the name).
They are used to signal events in household appliances, cash registers, cars, alarm systems, etc.
The buzzer BA9s 18-30V has an intermittent signal and works in the voltage range of 18-30V.