Features: Ensuring safety of your batteries with our 4S 40A Battery charging Protective Board, provide balance and Protective for 14.8V Cell Module. This Protective board features lightweight build, ensuring stable performances and durability for all your battery needs. Ideal for DIY enthusiasts, hobbyists, and professionals who work with batteries, including 18650 and batteries, without size limitations. With its low current consumption and multiple protections against over discharge, over current, and over charge, this board ensures efficient and safe charging and discharging cycles for your devices. Perfect for safeguarding 4S battery packs in solar charging systems, electric scooters, portable electronics, or industrial equipment where stable electricity control is critical. Specifications: Size:Approx. 37mm/1.45inch Package Includes: 4Pcs Protective Board note: 1.Please allow 1-2cm errors due to manual measurement, making sure that you not mind before order. 2.Due to the differences between different monitors, the picture may not reflect the actual of the item.