Features: Ensures stability of your 21V lithium batteries with our high efficiency Protective board, safeguarding against overcharge, over discharging, and short circuits. Crafted from ABS materials, this Protective board offers multiple layer of security, ensuring reliable and safe operation for your devices. Ideal for electronics enthusiasts, power tool users, and professional requiring lithium battery Protective, this board meets diverse needs. Perfectly suited for use in power tool and electronic projects, enhancing overall device performances and reliability. Elevates your equipment's efficiency and safety with this essential accessory, suitable for anyone battery management solution. Specifications: Component:ABS Type:B/A Size:Approx.4x4.6cm/1.57x1.81inch Package Includes: 1Pc 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.