WrightSocks Double Layer Merino Wool Trail Crew Socks, LG, Grey Wool/Polyester/Nylon/Lycra All the benefits of Merino wool in a light weight performance trail sock Wrightsock Double Layer provides year round performance with no blisters - guaranteed Inner layer promotes a cool, dry, 'skin friendly' environment with no wool against the skin Outer layer offers the thermal benefits and durability of Merino wool Designed for all activities where lightweight is preferred; running, biking, walking, hiking, racing