Yaktrax Thermal Insoles, One Size/Trim to Size, Pair. The perfect solution to cold, clammy feet. Made with multiple layers of insulating materials, these insoles help retain your body's natural heat, while wicking away unwanted moisture and providing a comfortable cushion for your feet. One size fits most/trim to size using the size chart provided on the reverse side of the package. Wear felt side up. Hand wash. Air dry. Rated up to -13 degrees Fahrenheit. Made of 97.66% Polyester, 2.34% Polyethylene.