Darn Tough's Vertex 1/4 sock is the lightest, fastest 1/4 sock they make. It's specifically designed for runners looking to lose the weight without sacrificing comfort and durability. Ultra-Light and ready to roll. True Seamless construction reduces hotspots and blisters. Ultra high stitch count creates a super comfortable sock with a streamlined fit like no other. No slipping, no bunching, no blisters. Fine gauge Merino Wool makes this a fast drying and breathable all weather sock that stays cool in the summer and warm in the winter. And since Merino Wool is naturally antimicrobial this sock repels bacteria and odor when you're laying down the miles. Still made in Vermont. Guaranteed for life.