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