The KOBALT TOOLS KB440-03 40v Max lithium-ion battery is a high-quality power source for various tools in your home or workshop. With a capacity of 4 amp hours and a voltage of 40 volts, this rechargeable battery provides the power needed for efficient and convenient tool operation. The sleek black design and model KB440-03 make it easily recognizable for charging and use with compatible Kobalt tools. Whether you're a professional or a DIY enthusiast, this lithium-ion battery is an essential accessory for your power tool collection.