Bosch Blue 18V cordless tools get their power from batteries that are part of the Bosch Professioanl 18V System battery platform. This allows you to exchange the Bosch Professional 18V batteries between different types of tools and you no longer need a separate battery for every drill or saw. In the combination sets of Bosch Blue, you won't find a battery for every tool, which saves a lot of money. As a professional user, you don't want to pause unexpectedly because your battery is empty. By working with the batteries of the Professional System, you always have a full battery at hand.