Drymax Hiking Socks have a special Dual Layer Moisture Removal System. This system instantly moves moisture from the skin, through the inner Drymax layer to the outer absorbent layer, keeping feet dry. Staying dry is critical to remaining warm, comfortable and safe in cold weather. Anti-bunching instep. Flat toe seam. Arch band holds sock in place. Terry loops inside increase insulation and protection. Y heel improves fit.