Horse Pilot Womens Sleeveless Puffer Jacket E Kelvin NavyThe E Kelvin sleeveless puffer jacket is crafted from a lightweight ripstop fabric for enhanced abrasion resistance Featuring integrated self heating technology built into the lining and connected to a rechargeable external battery, the carbon nanotube textile panel delivers warmth on demand The technology is activated via a button on the side of the jacket. Temperature can be adjusted using the button or through the "iwarm3" app, available for