The core of Browning’s AddHeat system is the heating element located in the upper back of a compatible garment, where it can effectively maintain core body temperature. Several popular Browning jackets and parkas also feature heating elements in the pockets to distribute heat and provide warmth for hands and fingers. The flexible, lightweight heating element is washable, and the AddHeat Power Pack includes a compact, rechargeable Li-ion battery that provides up to 51/2 hours of continuous heat, simple to use Micro-CPU controller, and 110-220 VAC charger. The system is conveniently recharged with either the charger or optional 12-VDC vehicle charger. Additional batteries are available to provide as much additional heat as needed. The battery weighs a mere 4.23 ozs. and can be recharged up to 500 times. (801) 876-2711; www.browning.com