By fusing together low-micron merino wool and polypropylene fibers, you get an incredibly strong yarn that allows a middleweight to act like a heavyweight in both warm and cold climates. They're strong, wicking, odor and blister resistant, breathable, quick drying... and they immediately recover in the wash. Made in the USA.

Content: 33% merino wool, 33% polypropylene, 26% nylon, 5% elastic, 3% lycra

Mens shoe sizes: Medium (5-8), Large (9-12), X-Large (13-15)

Womens shoe sizes: Small (4-7), Medium (8-11)