The SMB-series (multi-frequency buzzers) offer the possibility to program several different frequencies. 

The choice of the frequencies is simply done by changing the capacitor value in a C-MOS driven circuit.

Audible signals are part of our daily life.  More sophisticated and distinctive functions are required for industrial purposes. These audible signals with multi-frequency programmability will become an important component that must be considered in every design of equipment, machines, household equipment, computers, communication equipment, control panels, etc.