The original, 100% waterproof, windproof breathable knee length sock. The inner lining is crafted from fine Merino Wool to insulate and regulate temperature making this perfect for use in colder weather conditions. Please note that these socks replaced the SealSkinz "Hiking Knee Length" sock and we have a mixture of old and new styles. Please call us if you would like a specific size in the old or new style.