Drive mode: If you can not provide frequency signal to the buzzer work, you can consider the inclusion drive line, give DC voltage can be. Another straight, fast staccato, slow staccato, different sound signals.
Size: size will affect the frequency, small size will be higher frequency
Voltage size: Vo-p calculation, with square wave drive, the higher the voltage, the higher the volume
Pinpitch: Piezoelectric buzzer specifications are numerous, often difficult to find exactly the same specifications, can first pick pitch like, the frequency of close trial.