The HART 20V 4.0Ah Lithium-Ion battery is an excellent addition, or start to any DIYer��s HART tool collection. This battery is compatible with all HART 20V power tools. It features Lithium-Ion technology to give you long-lasting and fade-free power to get you through any project you decide to take on. This battery is designed to be compact and lightweight for more maneuverability and while reducing user fatigue. Whether you are maintaining your yard with HART outdoor tools, cleaning and maintaining your car with HART automotive tools or keeping cool and entertaining with HART lifestyle tools, the HART 20V 4.0 Ah battery is there to provide the power you need when you need it with 4x longer runtime than the HART 20V 1.5 Ah Lithium-Ion battery. This battery is sold as a single battery and does not include a charger or a tool. The 20V one battery system allows you to interchange the battery on all 20V HART products. It powers all HART 20V tools, outdoor, automotive and lifestyle items 4X Longer Runtime On-Board Fuel Gauge Battery chart that is on the back of the packaging Works with All HART 20V Tools Fade free Lithium-Ion power Includes: 4.0Ah 20V Lithium-Ion Battery Compared to a 1.5Ah HART Lithium-Ion Battery tested on a HART Hammer Drill Battery: 20V Lithium-Ion