General description 4X Lithium Battery Power Alarm is designed for use with RC helicopters, quadcopters, and cars. This alarm features LED indicators that provide real-time feedback on battery voltage levels, ensuring optimal performance and safety during operation. Technical specifications Material: PCB + LED Compatible with: 2-3S LiPo batteries Tested battery voltage (above 3.6V) for 2S LiPo battery: 2 LED lights Tested battery voltage (above 3.6V) for 3S LiPo battery: 3 LED lights Cell voltage below 3.3V triggers red light and alarm Measurement allowed error: +/- 1-3 cm Package list 4 x Lithium battery power alarm Other information Note: Light reflection and different displays may cause the color of the item to differ slightly from the actual product.