Finally, a lightweight sock that can multi-task. When you infuse polypropylene with Silver Technology, you get unmatched versatility. They repel water, regulate body temperature and are reinforced and padded in all the right places to avoid blisters and bunching. They are great as a hardcore activity standalone sock all year long, and they perform super as a liner in extreme conditions. Boot height, men’s sizes M (5-8), L (9-12), XL (13-15). Made in USA of 77% Polypropylene, 17% Nylon, 3% Elastic 3% Lycra.