Lipo Tester is used to detect battery voltage of 1S-8S lithium. It helps safeguard the type of battery overload and over ##flow. The buzzer with red led flash when the voltage is below the set point. The default setting is 3.3V that can be changed. This lipo tester is applicable for 1S-8S / Lipo / Li-ion / Li Mn / Li-Fe battery, RC Quad copter, helicopter, multicopter, car, boat and airplane etc.