The SmartWool PhD Snow Medium Sock offers increased performance and snow-specific technology for spending long days at the resort or in the backcountry. Made from a blend of naturally-antimicrobial merino wool and nylon, these socks include Indestructawool technology to keep them going session after session. A 4-degree elite fit system provides stretch and comfort, while body-mapped mesh zones allow your feet to breathe while chugging up the skin track.