Smartwool Women's PhD Ski Medium Sock, Black/Berry size M 66% Merino Wool, 32% Nylon, 2% Elastane Medium Cushion: Medium cushioned shin and foot for impact absorption and warmth. PhD = Built for Performance in the Highest Degree. Mesh Venting: Women's-specific mesh ventilation zones provide additional breathability and moisture management 4 Degree Elite Fit System: Uses two elastics for greater stretch and recovery to keep the sock in place. ReliaWool: Patented ReliaWool technology in high impact areas provides superior durability. Narrower profile provides perfect women's specific fit - Flat knit durable toe seam Sock Height: Over the Calf - 13" overall height Knit in USA of Imported Yarn Style: SW0SW264