The Buzzer (Peizo sounder) emits an audible tone when connected into a circuit. It is polarity sensitive and must be connected with the correct polarity (+/-) in order to operate correctly. 
 
Changing the level of input Voltage produces different sound level outputs.
 
Features securely fixed components mounted onto a sealed ABS enclosure with non slip rubber feet. 
 
Also avaialable as a front of class magnetic demonstrator.