The JHE20BFinder is a tiny 5v buzzer with integrated battery.  This allows you to locate your drone even if the main battery has disconnected as it has its own built in rechargeable battery.  THe buzzer is compatible with all Betaflight controllers and will be charged via your flight controller..

Key Features

• Item name: JHE20B Finder
• Size:22*12*9.5MM
• Weight:2.7 grams

How to turn off the buzzer

• Press and hold the release button for more than 2 seconds, the JHE20B Finder turns off the sound.
• The JHE Finder is compatible with all BF and CF flight controls.
• Just connect to the buzzer interface of the flight controller and it will work.
• When the flight control wiring is correct, the multi-rotor aircraft is powered on, and the flight control power supply will automatically charge the JHE42B_S Finder (the red LED will light to indicate that charging is in progress,
• Red LED on means the device is charging, Red LED off means charging is completed; red light flashing means flight controller is powered off, the unit wait 30 seconds before starting the beeper alarm..

How to connect

The image below shows the JHE42 finder, but the connection and pinout is the same.