Milwaukee Jacket M12 12V Lithium-Ion Heated Front and Back Heat Zones All Sizes and Colors - Battery Not Included - (Large, Black) Powered by M12 REDLITHIUM Battery Technology, Milwaukee M12 Heated Jackets use carbon fiber heating elements to create and distribute heat to the chest, back, and front hand pockets. For use in abrasive environments, ToughShell Stretch Polyester delivers 5X Longer Life than previous softshell jackets and provides wind and water resistance to survive the elements.