Designed to be worn close to the body, under your outer jacket, or over a thin polyester base layer. 7V heating system lets you enjoy hours of tailgating, hunting, sports, or working outside in a cold environment. Four-way stretch softshell fabric that's breathable, flexible, and durable. Microwire­™ Heating Technology utilizes patented micro-sized stainless steel fibers intertwined and encased in a proprietary waterproof coating. Four Microwire™ heating zones: collar, chest (2), and back. Durable, rechargeable 7-volt lithium Ion batteries power with an integrated microprocessor and LED switch gives you real-time battery status and power level monitoring. Heat lasts up to 8 hours. Lifetime Microwire™ Warranty from manufacturer. Jacket includes:. Gerbing 7V 3,400 mAH Rechargeable Battery. Single Wall Charger.