• Battery monitor function :Hold the button 3 seconds to enter the setting of the voltage threshold;Press button to set the alarm threshold between 3.4~3.7V/Cell(red LED);The value will be saved & exit if no action within 10 seconds
• Discovery buzzer function : It is easy to use the function, Just plug it in one Aux channel(e.g. Gear). Move the toggle switch to one side or another side, the BM3in1 will alarm "BeBeBeBeBe" & blue LED blink
• Signal loss alarm function : It can warn you if you turn off the transmitter first by mistake, if you have trouble finding a model in the long grass
• Please see the manual as the last picture on the left

 
--
It is a 3in1 gadget with LiPo Battery monitor, Discovery buzzer & Signal loss alarm functions. Specifications: 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 1. Battery monitor function (F1) Hold the button 3 seconds to enter the setting of the voltage threshold. Press button to set the alarm threshold between 3.4~3.7V/Cell(red LED) . The value will be saved & exit if no action within 10 seconds. 2. Discovery buzzer function (F2) It is easy to use the function, Just plug it in one Aux channel(e.g. Gear). Move the toggle switch to one side or another side, the BM3in1 will alarm "BeBeBeBeBe" & blue LED blink. 3. Signal loss alarm function (F3) It can warn you if you turn off the transmitter first by mistake, if you have trouble finding a model in the long grass... Integrated lipo display, finder and signal loss alarm function, suit for fixed-wing copters, helicopters, multicopters, RC cars, etc.