The DCB606 20 V/ 60 V max battery pack changes voltage when you change tools, powering a line of powerful 60 V max tools, 120 V max tools, and backwards compatible to existing 20 V max tools and chargers. The battery pack is smart enough to know when to provide runtime for 20 V max tools (6.0 Ah) and power in the new 60 V max and 120 V max tools. Battery provides long run-time and battery life Three-LED fuel gauge system allows immediate feedback on state of charge No memory and virtually no self-discharge for maximum productivity and less downtime.