Sockguy Wool 6" Crew socks are made from 75% TURBOwool, a superior blend of 50% Polypropylene and 50% Merino wool, which provides five times the strength and durability of Merino Wool alone. Shrink-resistant and itch-free. Easy-Fit??? Cuff, Stretch-to-Fit??? sizing system. These socks will keep feet dry and warm in all weather conditions, warmer in the winter, cooler in the summer. Same great sock as the Classic collection, but with the unique TURBOwool yarns.