Compatible with M12 Heated gear USB port to charge electronic devices. Compatible with M12 compact & XC batteries On-board fuel gauge The Milwaukee M12 power source is compatible with all M12 Battery Packs, features a 2.1-amp powered USB port that charges tablets, smart phones, mp3 players, and other portable electronic devices. This smart-charge port identifies the electronic device being charged, delivering fast, safe charging. The adapter features an on-board fuel guage, and is compatible with all M12 Heated Gear, providing up to 6 hours of continuous heat on a single charge. Battery Not included.