Features of the Smartwool PhD Ski Light Elite Sock Indestructawool Technology Features a wool-based, patent-pending yarn and construction method for exceptional durability and comfort 4 Degree elite Fit system Uses two elastics for greater stretch and recovery to keep the sock in place Mesh ventilation zones designed specifically for male skiers provide optimum temperature regulation and moisture management 200 Needle construction provides High-Density, low-profile cushioning Virtually Seamless toe Made in USA