IT'S ALL ABOUT THE SOCK - THE SMARTWOOL PHD SKI MEDIUM PATTERN SOCK.A sock that is too bulky will leave your foot aching by the end of the day on the mountain, and one that is too light won't offer enough warmth. Luckily, the Smartwool PhD Ski Medium Pattern Sock combines both for an exceptional ski sock. Made with merino wool for incredible warmth and combined with strategically placed ventilation zones, your feet will be in that perfect warmth zone without overheating. FEATURES61% merino wool, 38% nylon, 1% elastaneOver calfAll-mountain skiing, all-mountain snowboardingReliawool padding on shin and footMesh ventilation strategically placed throughout sock4 Degree Elite fit system