Bosch HDS181A-02 18V Lithium-Ion 1/2" Compact Tough Hammer Drill/Driver Kit ,SlimPack Batteries with 2.0 AH battery Durable, heavy-duty chuck for better bit retention and great torque transfer Innovative, lighter 18-Volt canned motor is more compact but the same power Compatible with all Bosch 18-Volt Lithium-Ion tools and chargers Unique Cool Pack Design: Special heat conductive housing and ribbing pulls heat away from inside the battery, keeping the battery cooler