Features: This 5x21700 18V lithium batteries shell set deliver high capacity and extended lifespans, perfect for highly power applications with its superior energy density and reliability performances. Featuring a customizable design with a protections board, it includes safeguards against overcharge, over discharge, and short circuits for enhanced safety and stability. Ideal for enthusiasts and users with basic skills, this battery set allows easy assembly and customization to repair or build batteries for devices. Suitable for Zhipu,Hongsong,Jingmi,Lomvum power tools replacing batteries, it offer versatile compatibility and efficient power solution for various equipment. Constructed from durability ABS and metal components, this battery shell set ensures easy installation and long term reliability for cost effective battery maintenance. Specifications: Component: ABS, PCB, metal Size: Approx.12.8x8.2x5cm/5.04x3.23x1.97inch Color: black and red for ,Zhipu,Hongsong,Jingmi,Lomvum Power Tool; Applicable battery: 5cell 21700 battery (battery is not included) Applicable scenario:Power Tool Repairs and Upgrades,Powering outdoor equipment； Package Includes: 1set Battery Case(with Screw &Accessories) 1pc Protections Circuit Board 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.