The Hestra Heated Liner turns a ski glove with a removable liner into a fully heated glove. A three-step control on the cuff adjusts heat output across the fingers and thumb, powered by a rechargeable 4000 mAh battery that runs anywhere from roughly two to ten hours depending on the setting. Flexible polyamide fabric, a microfleece lining, and G-Loft synthetic insulation keep hands warm even before the heat kicks in, and the liner slips easily into the Hestra Heli Ski glove and mitten or other Hestra gloves with a high cuff and a detachable liner. What Our Gearhead(R) Experts Are Saying:"I ran mine on medium through a full day of lift-served skiing and never had to reach for hand warmers. Getting the glove size right made a real difference, since too much room between the panels and my fingers meant less heat actually reaching them."