The merino wool Heavyweight OTC Wader Socks for warm, dry feet when cold weather fishing.Don't ruin winter fishing with cold feet! Orvis used the heaviest weight merino wool fiber contents and built winter-ready, over-the-calf warmth OTC Wader Socks, tested in conditions that would have less-committed anglers inventing excuses. Given their heavyweight, thick nature, gone are the days of doubling up socks in attempts to stay warm. These socks are built to keep you in the game all day. Because they're patterned after the contour of our wader booties and boots, expect a seamless fit with reinforced zones in problem abrasion areas like the heel, toebox, and the top of your ankle where wading boots end. Ribbed arch eliminates bunching and ensures comfort. Wool/nylon/spandex. Made in USA.