BP1870 - Heat Factory Battery Powered Toaster Muff: Heat Factory Battery Powered Toaster Muff combines time tested design with modern technology. Embedded with proprietary heat retention, efficient heating elements, and built for the outdoors the battery powered toaster muff is the ultimate way to keep your hands warm. Soft fleeced interior and a waterproof shell to protect anything you put in the large storage pocket. Provides over 6 hours of heat with the included lithium-ion battery or provide your own for longer heat. The Battery Powered Toaster Muff from Heat Factory is a valuable addition to your outdoor activities.