This is a 3in1 LiPo Battery monitor, Discovery buzzer & Signal loss alarm functions.
Built-in ultrahigh brightness LED & twin loud buzzers.

Item Name: Signal Loss Alarm Loss Aircraft Finder
Working voltage: 5.2-26V DC, 2-6Cells LiPo
Standby current less than 10mA
Working current, Max 120mA (blinking & beeping)
Voltage threshold setting: 3.4-3.7V/cell (Red LED)
Twin loud buzzers, 85db each
Ultrahigh Brightness LED, 20lm, 0.2w, Blue
Size: 20x30x6mm,
Weight: 7g

Features:
Suit for fixed-wing copters, helicopters, multicopters, RC cars, etc
With Battery monitor function
With Discovery buzzer function
With Signal loss alarm function