Features: Designed as a direct replacement for 18V battery packs, this high compatibility protections board ensures seamlessly fit with BL1830, BL1840, BL1850, and BL1860 models, featuring smart circuitry to prevent overcharging, over discharging, and short circuits for enhanced safety and longevity. Made from premium PCB, it delivers stable power output under heavy loads, and its user friendly structure allows quick installation without special tools or skills. Equipped with LED display light, it monitors the battery health in real time, allowing users to know the battery charging and discharging at any time. Perfect for home workshops or professional job sites, it provides reliabled protections during demanding tasks like drilling, cutting, or sawing to extend battery life. It has excellent heat dissipation, improves heat dissipation efficiency through reasonable layout, reduces the risk of overheating, and maintains the optimal working condition of the battery. Specifications: Size: about 5x3.5cm/1.96x1.38in Component: PCB High temperature resistant Support：LED light For 18V BL1830 BL1840 1850 bl1860 Package Includes: 1PC Battery protections board note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution