Fit and Design: Built with Gerbing Microwire Technology that provides first-class heating performance Easily slips under your jacket and over a base layer or shirt for hours of body-warming comfort 100% nylon exterior with 100% polyester interior Technology: Microwire heating system includes 3 built-in heating panels strategically placed on the chest and back Touch-button control technology Additional Details: Estimated Heating Times: 100% Power (4 red/blue lights) - 2 Hours 75% Power (3 red/blue lights) - 3 Hours 50% Power (2 red/blue lights) - 5 Hours 25% Power (1 red/blue lights) - 8 Hours Includes: (1) Gerbing 7-Volt Vest (1) Gerbing 7V 2,600 mAh Battery (1) USB Charging Cord Gerbing Lifetime Warranty