1-8S Low Voltage Buzzer Tester + 2-6 Cell LiPo Digital Battery Checker for DJI Quadcopter

This 1-8S LiPo / Li-ion / LiMn / Li-Fe 2in1 Adjustable Low Voltage Warning Alarm Buzzer Digital Battery Tester + 2-6 Cell LiPo Digital Battery Voltage Checker for DJI F330 F450 F550 Multicopter RC Models includes two battery voltage checkers. 1S-8S one is an alarm that you can put in your model to know when the voltage is low, especially aircrafts, so you can land safely (absolutely needed). The other is a battery checker to use prior to installing your battery.