Design and Details No slipping, no bunching, and no blisters Fine Gauge Knitting: Unprecedented durability 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: Ultimate fiber for breathability and comfort in all conditions True Seamless: Undetectable seam fusion for an ultra smooth, invisible feel.