The Worx 20V/4Ah replacement battery set is designed to keep your Worx tools charged and ready for use. With a capacity of 4 ampere-hours (Ah) each, these batteries offer long life and low self-discharge thanks to lithium-ion technology. This means you can use your tools for extended periods without having to recharge frequently, and the batteries retain their charge even if they're not used for a while. Furthermore, unlike older batteries, they have no memory effect, so they can be partially charged or discharged without compromising their capacity over time. These batteries are compatible with several 20V devices in the Worx line, offering a convenient and versatile option for powering a variety of power tools. The set includes two batteries, ensuring you always have a spare battery ready to keep working without interruption.