Dachstein Woolwear 100% Austrian Boiled Wool Extra Warm Knee Socks Made in Austria of 100% boiled wool essential for comfort in cold weather since wool can absorb 30% of its weight in water and maintain its insulating qualities. Please do not use the Amazon size chart for reference. See additional images for the Dachstein Woolwear size chart. Socks are European, but listed here in US Men's Shoe Size for convenience. Extra Warn Knee Socks of 3 ply wool in 2 plys of heavyweight 4.4 and 1 ply of 7.0. No other knee sock has this much heavy wool. The warmest knee sock in the world---extra warm, extra thick, extra ordinary!!!!