Patent pending ReliaWool Technology in high impact areas provides the longer lasting protection to keep feet comfortable. 3.75" overall height, alternating 1x1 welt, single layer 1x1 ribbed top. * 52% Merino Wool, 44% Nylon, 4% Elastane, washer and dryer friendly * Men"s sock sizes - Medium (fits US shoe size 6-8.5) Large (fits US shoe size 9-11.5) X-Large (fits US shoe size 12-14.5)