A mid-calf length thermal sock. The Merino wool terry loop piles fully cover the inside of the sock, offering the exceptional thermal protection as well as comfortable fit to mid calf. • Outer : 96% Nylon, 3% Elastane, 1% Cuff Elastics. • Interlining: Porelle® membrane. • Inner: 38% Merino wool, 38% Anti-pilling acrylic, 24% Nylon.