Features: Designed specifically for 40V OP4040/OP4026A/OP4050 tools, this 20cell 18650 battery housing set features a built in PCB protections board with overcharge, over discharge, and short circuit safeguards for reliability power solution. Crafted from durability ABS and metal components, the lightweight shell organizes 20 replaceable 18650 lithium batteries in an impacts resistant structure while maintaining tool portability and thermal stability. Ideal for enthusiasts and power tool users seeking customizable energy upgrades, this assembly friendly set not requires technical expertise for secure installation in cordless equipment. Perfect for extended outdoor projects, workshop repairs, or highly demand devices like LED work lights and electric garden tools requiring sustained 40V power output. The module design promotes battery reuse across multiple 40V compatible systems while delivering commercial grade protections through its layered safety architecture and ergonomic housing. Specifications: Component: ABS, PCB, Metal Size:Approx.16.5x10x8cm/6.5x3.94x3.15inch Color: black Applicable battery: 20x18650 battery (this product does not include batteries) for 40V OP4040/OP4026A/OP4050 power tool; Applicable scenario:Handmade projects,Repair and rebuild power tool, Package Includes: 1set Battery Shell(Battery not included) note: Please allow 1-3cm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual item color.