【Constitution】: This DC 3-24V piezo electronic tone buzzer is mainly made up by multivibrator, piezoelectric buzzer chip, impedance matching unit, resonator and shell 【Working State】: Multivibrator is composed of transistors or integrated circuits. When switched on, multivibrator vibrates and outputs audio 【Continuous Sound】: If our 85 to 95db electronic sound buzzer is connected to rated power, the buzzer will sound continuously 【Sound Drive】: The impedance matcher will drive piezoelectric buzzer sound 【Convenient Control】: This 100mm alarm continuous sound cable buzzer can be controlled conveniently