Description of Lorpen Coolmax Fx Silk Lined Shorty Walking Socks - Women's Fast Dry Coolmax fx effectively inhibits the growth of odor causing bacteria for the life of the sock. The lining of natural silk significantly reduces the chance of blisters and abrasion plus adds an extraordinary level of comfort. Features: Nylon outer layer - durability Middle layer of Coolmax Fx - fast drying, antibacterial Inner layer of natural silk - maximum gentleness More open knit over the instep to reduce bulk, improve fit and enhance moisture management More cushioned knit on the sole where you need it