PhD Outdoor Light Pattern Mid Crew Socks boast SmartWool's 4 degree elite fit system and ReliaWool high density impact zones for all day comfort with an improved fit and greater durability. . Light half cushion for varied trail and road terrain. Mid crew height overall height: 6 in.. Merino wool, nylon, and elastane fabric blend. SmartWool delivers soft, itch free comfort, even foot temperature, moisture management, and odor control. 4 Degree elite fit system uses two elastics for greater stretch and recovery to keep the sock in place and improve fit. 4 fit bands at ankle, arch, upper and lower instep wrap and support the foot for more comfort, faster flex and recovery. ReliaWool technology in high impact areas provides longer lasting protection to keep feet comfortable. Strategically placed mesh ventilation zones provide ventilation for temperature and moisture management. Flat knit durable toe seam for high burst strength. 2x1 ribbed welt, 1x1 ribbed leg. Machine wash warm, inside out, gentle cycle, tumble dry low or lay flat. Knit in the USA of imported yarn.