The Integy LiPo Voltage Checker and Warning Buzzer can be used with 1-6S LiPo, Li-ion, LiMn and LiFe batteries. The warning alarm will buzz and turn on red LED light when voltage is less than 3.3V. Useful in flight when you cannot see the lights.

Specs
Cells: 1-6S
Voltage Decection Precision: +/- 0.01V
Unit Voltage Display Range: 0.50-4.49V
Total Voltage Display Range: 0.50-25.9V
1S Test Mode Voltage Range: 3.3-13.2V
1S Test Mode Detection Precision: +/- 0.5%
Low Voltage Buzzer Alarm Mode for 2-6S