SmartWool PHD Ski Light Socks 31% nylon 4 Degree Elite Fit System - 4 Compression Bands and flex zones that provide high performance and a secure fit. Two elastics provide greater stretch and recovery to keep the sock in place. ReliaWool Technology - Featured in high impact areas, provides the longer lasting protection to keep feet comfortable. Mesh Ventilation Zones - Strategically placed, these provide ventilation for temperature and moisture management. 13" overall height Fabric: 67% Merino Wool, 31% Nylon, 2% Elastane