The PhD Ski Light provides superior fit, comfort, durability, and versatility with its improved 4-Degree Fit System. • 4-Degree Banded Fit System for all day performance fit • WOW Technology in High Density Impact Zones to reduce shock & abrasion • SmartWool inside for moisture, temperature, and odor control • Duroyarn™ reinforcement for added comfort & durability • Strategic Mesh Zones for maximum ventilation • 67% Wool, 32% Nylon, 1% Elastic |