Ulvan Active is a warm merino wool sock. Toe and heel are reinforced for durability. The cuff is higher to ensure better fit and that the sock stays in place during use. Extra mesh at ankle for better wicking. Active is a tick, extra-warm terry sock in merino wool for everyday and sports use. Perfect as a second-layer sock on extra-cold days. Size markes on sole. Warm, thick merino wool sock Ideal for colder days Ideal for every member of the family Oeko-Tex and Woolmark Blend certified Materials 66% Merino Wool, 30% Nylon, 4% Lycra