Milwaukee REDLITHIUM FORGE XC8.0 Battery Pack MXFXC608 w/ Portable Battery Extension Battery is new still in box MX Fuel Redlithium Forge XC8.0 battery pack delivers up to 33% more runtime in a lighter weight design, has Cool-Cycle capability for high-speed cooling, and the longest life versus Redlithium batteries MX FUEL Portable Battery Extension allows you to operate any MX FUEL Equipment while taking all of the weight of the MX FUEL battery pack out of your hands, delivering lighter tool weight and less fatigue on handheld equipment