URUAV UR8 5V Duo Buzzer 31x13mm Over 110dB BB Alarm 3 Working Modes w/ Battery & LED for RC Drone FPV Racing

Having 3 working modes.

1.  Compaitble with BF/CF flight controller like normal buzzer ( such as F3/ F4/ F7 Flight Controller). 
     Just need connect it to flight controller's buzzer port, then it can work well. 

     While you build fc well on quad and power to quad, the fc (+5V) would charge to this buzzer automatically.
     ( Red LED points at in charging)
 

2.  Can power itself to beep even the quad's battery has been ejected.

     About 30 sencond later, it will beep in 110DB and LED would be light in white.

3. Using PWM Receiver Signal (1000us-2000us) to make it beep or disarm it.
    Over 1700US, open Buzzer and make it beep.   Lower to 1650US, disarm buzzer. 
    Compatible with Airplane etc.
 

Disconnect main battery, hold disarm button on buzzer for 2 seconds then release.