Need a sock that offers maximum warmth, maximum comfort and maximum durability in all outdoor extreme activities? The Darn Tough Mountaineering Micro Crew Cushion sock is designed for all this while staying put during your outside adventure.KEY FEATURESPerformance Fit: Means o 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.Merino Wool: The ultimate fiber for breathability and comfort in all conditions.Extra Cushion: Their thickest, burliest and highest density cushioning makes for a big, bad monster of a sock.Over the Calf Height: The name says it all. The ultimate height for keeping the outside out.Material:73% Merino Wool 25% Nylon 2% Lycra® SpandexGurantee:For Life: No strings. No conditions. For life.