This warm boot has kept hunters toasty for nearly a decade with a 5mm CR Flex-Foam fleece liner with the added 2mm thermal foam under foot. Its a proven combination at frigid temperatures embraced by hunters on the stand and in the blind. Warm Fleece Lining 2mm Thermal Foam Under the Footbed 5mm CR Flex-Foam EVA Contoured Molded Midsole MS-1 Molded Outsole Comfort Topline New Camo Temp rating -40C to 4C CR Flex-Foam adjusts to the unique contours of your foot to create a comfortable and stable foundation while resisting blisters and chafing