This 4.0Ah battery is compatible with all Hyper Tough 20V tools. You will never run out of runtime while having this additional Hyper Tough Battery on hand! Lithium-Ion Batteries have a high energy density which provides a longer discharge time and provides consistent power through the charged cycle. Unlike NI-Cad batteries which slow down as energy is depleted, these Lithium-Ion batteries run full strength until all energy is expended. Once charged Lithium-Ion batteries also have a longer shelf life and will not lose power when not in use. This battery is sold as a single battery and does not include a charger or a tool. * Key Features;* Compatible with all Hyper Tough 20V Tools;* The higher capacity battery provides 2* runtime and power for more demanding tools * Includes: 1*20V 4.0Ah Battery;* Longer run time;* Specification:;* Rated Voltage 20V * Capacity 4.0 AH;* Weight: 1.55 lbs. (0.7 kg);* Model # 8711.1;* 2-Year Limited Warranty