Introducing the Katsu Spare battery, perfect for your power tools. This 21V Lithium-Ion (Li-Ion) battery has a capacity of 4000mAh, providing long-lasting power for your DIY projects. It is compatible with the 102600 model, making it a reliable replacement for your old battery. With the brand name Katsu, you can trust that this battery is made with high-quality materials and will provide consistent performance. It is ideal for use in power tool batteries, power tool & air tool accessories, and home improvement DIY tools & workshop equipment. Don't let a dead battery ruin your project, get the Katsu Spare battery today.