Don't let the cold stop you from taking one last run: the PhD Ski medium delivers maximum warmth and breathability when the going gets cold. Patent-pending Indestructawool technology provides ultimate durability to make sure your socks are ready to go, run after run. Made with our 4 Degree elite fit system for a sock that doesn't bunch, slip, or bind and a women's-specific fit for a narrower heel and overall slimmer fit.<br><br><b>PhD</b><br>Built for Performance in the Highest Degree<br><br><b>Women's Specific Fit</b><br>Narrower profile provides perfect women's specific fit<br><br><b>Indestructawool<br></b>Indestructawool technology features a patent-pending construction method for exceptional durability and comfort<br><br><b>4 Degree Elite Fit System</b><br>Uses two elastics for greater stretch and recovery to keep the sock in place<br><br><b>Mesh Venting</b><br>Women's-specific mesh ventilation zones provide additional breathability and moisture management<br><br><b>Medium Cushion</b><br>Medium cushioned shin and foot for impact absorption and warmth<br><br><b>Care</b><br>Machine Wash Warm Gentle Cycle. Do Not Bleach. Tumble Dry Low. Do Not Iron. Do Not Dry Clean.