DeWalt 20-Volt/60-Volt Maximum Lithium-Ion 9.0Ah Battery & FLEXVOLT 20-Volt/60-Volt Max Lithium-Ion 6.0Ah Battery Pack

The DEWALT DCB609Y FLEXVOLT Battery pack changes voltage when you change tools. It Powers a new line of 60-Volt maximum Brushless tools and 120-Volt maximum Brushless tools. This pack is also backwards compatible with 20-Volt maximum tools and chargers. The DEWALT DCB606 FLEXVOLT Battery pack changes voltage when you change tools.