Reinforced footbed and Achilles cushion improves the comfort of our socks and helps them last longer. Merino Wool is at home on the trail, naturally moving moisture to keep feet fresh and dry in all weather. Guaranteed for Life - If these socks wear, tear, or develop holes, Darn Tough will replace them; No strings; No conditions. Midweight with Cushion - A warm and extremely comfortable choice when conditions demand it, this fine gauge knitted sock provides mid-level cushion density under your foot; True Seamless technology allows for an undetectable seam fusion for an ultra-smooth, invisible feel.