Rated voltage: 12Vp-p
Operating Voltage:1-30
Rated Current(MAX):5mA
Min Sound Output at 10 cm: 80dB
Resonant Frequency: 4000Hz
Tone Nature: single
Lead pin material: Red copper
Operating Temperature: -30℃ - +85℃
Storage Temperature: -40℃ - +85℃
Housing Material: NORYL
Weight: 1g

In common parlance a Buzzer is a signaling device that is not a loudspeaker. It can be mechanical, electromechanical, or electronic (a piezo transducer). 

The application of piezo buzzer in household goods, medical devices and even very loud sirens. When a lower frequency is required an electromagnetic buzzer can fill the need. These are very common in automotive chimes and higher end clinical diagnostic devices.