If you're craving an intensely stripped down sock that leaves no slack in the system when transferring power to your edge, the RFL delivers. Just enough warmth and way more than enough power. Lightest sock for race day or anyone looking for a lighter-than-air feel from a tougher than hell sock. The name says it all. The ultimate height for keeping the outside-out. Details: 46% Merino Wool, 50% Nylon and 4% Lycra Spandex blend, no slipping, no bunching, and no blisters, unprecedented durability and unique ''put it on, forget it's on'' feel, pulls moisture away from skin, fast drying, cool in the summer, warm in the winter, repels bacteria and odor, the ultimate fiber for breathability and comfort in all conditions, undetectable seam fusion for an ultra smooth, invisible feel. Material: Merino Wool, Nylon, Lycra Spandex.