This product is designed to fit the children's Sorel Glacier Boot. It will not fit other brands of winter footwear products properly. Features include a polypropylene core for moisture wicking and insulation, a polyester Minktex (green inner layer) fabric for moisture wicking, Radiantex foil to reflect heat inward, and a polyester/viscose blend outer layer to hold moisture away from the foot. Needle construction allows for efficient wicking of moisture.