With the built-in battery, it can work as a standard buzzer that controlled by transmitter or standalone buzzer that beeps loudly after the main battery has been ejected.
Super loudly that the volume can reach up to 110 dB.
The LED can flash automatically when the built-in light sensor detects the light darkness.
Two ways to disarm the buzzer, via the switcher on the buzzer or plug-in-out the quad battery.
Be compatible with both FPV quadcopter and RC Airplane.