This is the 5V loud buzzer from Matek. But what makes it loud I hear you cry?! Well this buzzer has a built-in MCU which makes it louder than your traditional 5V active buzzers. 

Specifications:

• Built-in MCU
• Working voltage range: 4.5-5.2V
• Power: 1W max
• Sound output: 90dB max
• Dimensions: 18x13x8mm
• Weight: 2g

Directions for use:

Resources:

For more information, check out the Matek DBuz5V Lost Model Beeper & FC 5V Buzzer manual.