Make sure your feet stay comfortably warm during cold-weather outdoor tasks with Yaktraxs cut-to-fit Thermal Insoles. Blended polar felt is fray-free and features an underlay of Radiantex to redirect body heat back to your feet, while also wicking away moisture to provide extreme warmth and dryness as you work. Polar-blend wool felt offers additional warmth, as well as superb cushioning. Plus, these insoles repel water to keep feet protected. Heat rated to13F. Wear felt-side up. Hand wash and air dry. Uncut insoles are the equivalent of a mens size 12-13. Simply trim each insole to your desired size and slip them inside your favorite pair of boots. One size fits most.