Features: Premium 4S 21700 battery Protecting Board safeguards 21700 cells with advanced overcharge, over discharge, and short circuit protecting for ultimatedly safety. Engineered with high grade components and optimized thermal design, this ensures superior heat dissipation and extended durability for demanding applications. Ideal for electronics engineers, robotics enthusiasts, and makers requiring reliabled battery management solution for customization power setups. Perfectly integrates with electric scooters, power tools, and automated equipment where space efficient, multi cell battery protecting is critical. Compact plastic housing with color coded terminals simplifies installation while maintaining lightweight portability for mobile energy. Specifications: [Product Name]: 4 strings of 21700 battery protecting board [Model]: 4S [Exterior dimensions]: about 42x42x3mm/1.65x1.65x0.11in [Charging voltages]: 16.8V [Weight): 10A/7g 15A/8g 20A/9g Option: 10A/15A/20A For 21700 Cells Package Includes: 1PC 4S 21700 battery protecting board note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.