Features: 1S battery level indicator module, can be used for auxiliary charging and discharging indication of Lion Li batteries. Only 2 wire need to be welded, no additional setting is required, and the application is very convenient. Mini size can be easily inserted into various electronic devices. Suitable for 1S 3.7V Lion Li battery. Build in four-way comparator, internal comparator with reasonable hysteresis for detecting four voltage point, easy to charge and discharge instruction. Specifications: Material: ABS Size: approx. 12.4x7mm/0.48x0.27inch Item Name: 3.7V 4.2V LI-ON LI-PO Battery Level Indicator Board Working voltage: 3.7-4.2V Super low current consumption:< 10uA High precised detection voltage: ±2% Pin description: B+ connection to the positive terminals of the battery B- connection to the negative terminals of the battery Package Includes: 1 Piece Lithium Battery Power Indicator Light note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.