THIS IS BATTERY VOLTAGE CHECKER AND LOW VOLTAGE BUZZER 3-IN-1 UNIT.

Special feature:
1S test mode test range 3.7 to 30V, (8 CELLS LI-PO) which means you can test the battery pack without balance connectors like RX battery pack etc., LiPb or other power source voltage.
In other words, this very little devise can be used as a simple digital voltage meter.

Loudly buzzer can be heard from distance, you can put this device on your plane and use it as on-board alarm, so you can hear the low voltage alarm during flight.

You can ajust the low voltage alarm volt from 2.7 v-3.8 v

Specifications:

Use for 1-8S Lipo/LiMn/Li-Fe
Voltage detection precision ±0.01V
Unit voltage display range 0.5-4.5V
Total voltage display range: 0.5 - 36V
1S test mode voltage range: 3.7-30V
Low voltage alarm mode for 2-8S
Alarm set value range: OFF-2.7-3.8V
Weight: 8.7g/ 0.31oz

When the voltage is below the set value, it will buzzer with red LED light, pre-set value 3.3V.
Push key which can change the voltage settings and save.

* Friendly remind:
The sound of the low voltage alarm is very big, so please be prepared when use it for the first time, and you can turn it OFF when use indoors.