Specifications:

Rated Voltage: A piezo buzzer is driven by square waves (V p-p).
Operating Voltage: For normal operating. But it is not guaranteed to make the minimum SPL under the rated voltage.
Consumption Current: The current is stably consumed under the regular operation. However, it normally takes three times of current at the moment of starting to work.
Capacitance: A piezo buzzer can make higher SPL with higher capacitance, but it consumes more electricity.
Sound Output: The sound output is measured by decibel meter. Applying rated voltage and square waves, and the distance of 10 cm.
Rated Frequency: A buzzer can make sound on any frequencies, but we suggest that the highest and the most stable SPL comes from the rated frequency.
Operating Temp.: Keep working well between -30℃ and +70℃.

How to choose:

Driving methods: AZ-xxxxS-x series with built drive circuit will be the best choice when we cannot provide frequency signal to a buzzer, it only needs direct current. Besides, there are different tone nature for you to choose, such as continuous, fast pulse, and slow pulse.
Dimension: Dimension affects frequency, small size result in high frequency.
Voltage: Driven by square waves (V p-p), the higher voltage results in the higher SPL.
Pin Pitch: The numerous spec. for the piezo buzzers lead to the difficulty in finding a spec. in facsimile, therefore we suggest that you can firstly choose a spec. with the same pitch and similar frequency.

How to choose a buzzer