The Klein Tools Portable Rechargeable Battery, No. KTB1, features a compact, pocket-sized design ideal for everyday use. The KTB1 offers the convenience to charge everyday essentials such as phones, headlamps, speakers, fans, and other job site accessories. The battery has a rugged exterior for added durability and illuminated ports for easy identification in low-lit environments. It features a 10050 mAh capacity battery with up to 18W of total power.