If other outdoor boot socks are too restrctive, give the Diabetic Ther mal a try. Unique relaxed fit with all-over thermal cushioning keeps feet warm and dry in the field or on the trail. Heavy cushioning throughout is the trademark of this weight. typically cushioned not only for comfort but for warmth as well. Cushion throughout the sock. 65% Acrylic, 19% Wool, 16% Stretch nylon.