Features: Designed specifically for power tools, this 21V battery pack case houses 5 18650 lithium batteries to provide stable and efficient power supply, making it practical for power tool accessories. Featuring a plastic shell with excellent impacts and pressure resistance, it incorporates multiple safety protections against overcharge, over discharge, and short circuits, and enables easy assembly in just 10seconds for quick installation. Ideal for DIYer enthusiasts, professional contractors, and automotive maintenance workers who require high performances power solution for their tools. Perfectly suited for diverse settings such as home DIYer projects, professional construction sites, and car repair workshops, enhancing tool endurances with this battery pack. Boosts compatibility and longevity by using this versatile 18650 battery case with various equipment, ensuring consistent performances across different power tool accessories applications. Specifications: Component:ABS Size:Approx.115mm/4.52''x75mm/2.95''x45mm/1.77'' Applicable batteries: 5pcs 18650 lithium batteries (not included) Package Includes: 1Piece Batteries Housing note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color of the item.