It can be used on triditional PWM receivers or FPV racing flight controller.
The tiny buzzer is drived by on board MCU. It can output louder sound than 5V active buzzers.

Features & Spec.:
– Built-in MCU
– Working voltage range: 4.5~5.2V DC
– Power: 1W Max.
– Sound Output: 90dB Max.
– Size & Weight: 18x13x8mm, 2g