Proprietary Mobile Warming® technology by Fieldsheer® is specially engineered for cold weather conditions. Fieldsheer® has developed Mobile Warming® comprehensive heating technology to keep you warm and comfortable. Our exclusive Mobile Warming® heating technology utilizes ultra-fine metal fiber heating elements powered by lightweight, rechargeable, and powerful Lithium-Ion batteries. The combination of unique materials, construction techniques, and innovative design results in the most advanced heated gear available. (less)