5PCS 1-8S 2 IN1 Lipo Li-ion Fe Battery Voltage Tester Low Voltage Buzzer Alarm
Use for 1-8S Lipo/Li-ion/LiMn/Li-Fe. (pre-set value is 3.3V). Alarm set value range:OFF~2.7~3.8V. Mini shape, no larger than a common key. With a push key by which you can change the value settings and save.