A Blundstone wool sock two-year NO-HOLE warranty tells you how confident Blundstone are that you will love these black Blundstone socks. Woven of pure, ethically sourced Merino wool, this natural fibre is the best material we know for sock-making. Wool fibres insulate while absorbing moisture and releasing it to the atmosphere for dry comfort. 75% Merino Wool, 20% Nylon, 5% Elastin. Special ribbing ensures socks stay up when pulled up, down when squished down, or anywhere in-between. (Sock fans, you know what we're talking about.) Braced arch for foot comfort and support. Best boot sock we've seen.