Features: Ensuring safety of your batteries with our 6mos/8mos 21v Battery charging Protective Board, provide balance and Protective for Cell Module. This Protective board features lightweight build, ensuring stable performances and durability for all your battery needs. Ideal for enthusiasts, hobbyists, and professional 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 charging, this board ensures efficient and safe charging and discharging cycles for your devices. Perfect for safeguarding battery packs in solar charging systems, electric scooters, portable electronics, or industrial equipment where stable electricity control is critical. Specifications: Component:PCB Size:Approx.9x6.2cm/3.54x2.44inch Package Includes: 2 Optional Package: Package 1 Include:1Pc Protective Board Package 2 Include:2Pcs 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.