Description This product is using for detecting 1S-8S lithium battery, and protect the battery from overheating or over discharging. Detect the voltage of each battery core automatically, support reverse connection protection.The factory default setting is 3.3V, press the button to change the voltage setting, and it will save your current setting automatically. Features - Color: Shown in the pictures.- Material:Electric components.- Size: Approx. 4 x 2.5 x 1cm or 1.6 x 1 x 0.4 inch (LxWxH).- This product is using for detecting 1S-8S lithium battery.- Detect the voltage of each battery core automatically, support reverse connection protection.- To know the working state of your battery anytime, protect the battery from overcharge and over discharge.- The red LED will flash, the buzzer will beeping when the voltage is below the set point.- The factory default setting is 3.3V, press the button to change the voltage setting, and it will save your current setting automatically.Packing list: 1 x Lipo Battery Low Voltage Tester Checker 1-8S Buzzer Alarm with LED Indicator for RC Helicopter Quadcopter