The Stanfield Waterproof Extreme Cold Weather Mid Length Sock is the original SealSkinz 100% waterproof, windproof and breathable sock amped up with the thickest insulation to take on adventures in the coldest and wettest weather and avoid such things as the numbness, blisters and frostbite you can get from wet feet. Take on frigid streams, icy terrain and deep snow and keep your feet dry and warm. These socks are made with a 3-layer bonded construction that fuses a waterproof hydrophilic membrane between a moisture-wicking, heat-trapping premium Merino wool lining and a 4-way stretch nylon exterior for great fit and wearability.