If you're a serious thru-hiker that's miles away from the nearest town, blow outs, blisters and other sock B.S. can be disastrous. That's why we built this sock to outperform and over-deliver when you need them most.FEATURES Performance Fit: No slipping, no bunching, and no blisters. Fine Gauge Knitting: Unprecedented durability and our unique “put it on, forget it’s on” feel. Fast Action Wicking: Pulls moisture away from skin. Fast drying. All Weather Performance: Cool in the summer, warm in the winter. Naturally Antimicrobial: Repels bacteria and odor. Guaranteed For Life: No strings. No conditions. For life. Merino Wool is fast drying, breathable and odor resistant for all-day comfort. True Seamless™: Undetectable seam fusion for an ultra smooth, invisible feel. SPECS Boot socks sit mid-calf for added protection and warmth. A sturdy companion. 64% Merino Wool, 33% Nylon, 3% Lycra® Spandex Additional warmth and protection are the signature characteristics of midweight yarns in the Hike/Trek category. CUSHIONING DETAILS CUSHION Cushion in the Hike/Trek category features terry loops under the foot reaching above the ankle for comfort and protection. FULL CUSHION The Hike/Trek full cushion socks feature terry loops throughout the entire sock for the ultimate rebound and comfort. SIZE CHART SOCK SIZE SHOE SIZE Women's Women's US Men's US EU UK S 4.5 - 7 2.5 - 5 35 - 37.5 2.5 - 4.5 M 7.5 - 9.5 5.5 - 7.5 38 - 40.5 5 - 7 L 10 - 11.5 8 - 9.5 41 - 42.5 7.5 - 9