A:
Redhead Extreme Cold Socks:
50% Pure Wool, 20% Hollofil, 20% Acrylic, 8% Stretch Nylon, 2% Spandex
Redhead All Purpose (Lifetime Guarantee) Socks:
88% Merino Lambswool, 10% Stretch Nylon, 2% Spandex
I like both socks, though the Extreme Cold feel like they compress my feet less than the All Purpose ones.