A favorite of thru-hikers and day-trippers alike, the PhD(R) Outdoor Light packs some serious trail power. Featuring a versatile, multi-sport design, this lightweight style includes Indestructawool(TM) technology for ultimate durability in high-wear areas. And, when it comes to comfort, Smartwool pulled out all the stops: the 4 Degree Elite Fit System provides a dialed fit and the signature Virtually Seamless toe offers extraordinary comfort in any trail shoe. The mid-crew silhouette sits at an ideal height for a low trail boot, while the women's-specific fit provides an overall slimmer fit and narrower heel. 57% Merino Wool, 40% Nylon, 3% Elastane. PhD(R): Built for Performance in the Highest Degree. Women's Specific Fit: Narrower profile provides a perfect women's-specific fit. 4 Degree(TM) Elite Fit System: Uses two elastics for greater stretch and recovery to keep the sock in place. Indestructawool(TM) technology features a patent-pending construction method for exceptional durability and comfort. Women's-specific mesh ventilation zones provide additional breathability and moisture management. Light Cushion: The ideal cushion for varied trail and road terrain. Sock Height: Mid Crew. Virtually Seamless(TM) toe. 7.5" overall height. Machine Wash Warm, Wash Inside Out. Do Not Bleach. Tumble Dry Low. Do Not Iron. Do Not Dry Clean. Made in USA of Imported Yarns.