Wool is king. These long, boot style socks are built to keep your feet and lower legs cozy warm and dry. Both have a wool inner layer, providing a perfect balance of warmth and moisture control in a wide range of conditions. The Italian Wool (black/grey stripes) socks are 80% wool and 20% Polyamide/Lycra. They add a little bulk and provide maximum warmth, but they are a little coarser than merino wool. The taller Merino Wool (black/grey patterned) socks are 75% Merino and 25% Polyamide/Lycra. If you have issues with the ‘feel’ of wool, you should probably stick with the thinner, slightly finer merino. M (5.5-9.5), L (10-12.5), XL (13-15).