Experience one of nature's finest fibers, Merino Wool. Our wool is soft against your skin and naturally moves moisture away from your feet while regulating temperature, so you stay cool in the summer, warm in the winter, and dry all year long. The Ultralight fits comfortably into lightweight technical shoes for a barely-there feeling. Pair these socks with your favorite outdoor activities like trail running or mountain biking for comfortable year-round wear. The FOUR (Quarter Crew) sits below the calf and is the tallest sock with our double-cuff construction. Our most popular cuff height for cycling and trail running. - Improved durability with high tenacity fibers in abrasion prone areas - Versatile mid-cushion option delivers lasting comfort and performance - Soft, natural Merino Wool - 63% MERINO WOOL / 35% Nylon / 2% Spandex - Made in USA