With ThermaCELL remote-controlled heated insoles, prolong your cold-weather activities while heating your frozen boots or shoes. Keeping your feet warm and toasty has never been this convenient. Water resistant and customizable to most foot sizes, adjust the temperature of your feet with the simple click of a button. With embedded and rechargeable lithium-ion batteries, each charge lasts 5 hours, and the batteries will withstand 500 recharges. Insoles heat just like a home thermostat, turning on to maintain a temperature. With two settings. Medium: 100°F. High: 110°F. Imported.In sizes: S(men's shoes 4½-5½, women's shoes 6-7), M(men 6-7½, women 7½-8½), L(men 8-8½, women 9-10), XL(men 9-11½, women 10½-13), XXL(men 12-13, women 13½-14).