XD-82B 12V Battery Level Indicator module LED 1, on-board precision voltage detection chip and power regulator chip 2, onboard four battery indicator LED lights, three colors display, red, yellow, yellow, green representing 20%, 50%, 80% and 100% of the electricity 3, set aside all the way battery testing interface, and two mounting holes located 4, PCB size: 22.2 (mm) x17.2 (mm) 5, Measuring Voltage = 3.7V recommended for Lithium Ion Batteries.