The Smartwool Performance Ski Full Cushion OTC are one of our most popular all-season ski socks. The 4 Degree Elite Fit System keeps the sock in place by using two elastics to give excellent stretch recovery. They feature wear-resistant Impact Zones on the shin, toe and heel for durability and a broad, upper calf height cuff for comfort under a ski boot. These are superb ski socks which are warm enough for the depths of winter but comfortable enough for spring touring. Indestructawool Technology Indestrucatwool is a wool and yarn construction method used by Smartwool to create a wool and synthetic fibre blend which gives the best comfort and durabilty. 64% merino 34% nylon 2% elastane Smartwool Performance Ski Full Cushion OTC