Design and Details Performance Fit: No slipping, no bunching and no blisters Fine Gauge Knitting: Unprecedented durability and the unique "put it on, forget it's on" feel Fast Action Wicking: Pulls moisture away from skin 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: Ultimate fiber for breathability and comfort in all conditions True Seamless: Undetectable seam fusion for an ultra smooth, invisible feel Ultra-Light: the lightest sock for race day or anyone looking for a lighter-than-air feel from a tougher than hell sock Over The Calf Height: Name says it all, ultimate height for keeping the outsideGAfa AfA'out 55% Nylon, 42% Merino Wool, 3% Lycra Spandex