Drymax Trail Run 1/4 Crew / Turndown Socks 65% Drymax/Olefin, 20% Polyester. 8% Nylon, 7% Elastaine Double welt (water resistant) increases leg protection Arch band holds sock in place Dual layers knit toether keeps feet dry, and the 1/4 Crew Turndown gives you a choice of sock height Flat toe seam and Y-Heel improves fit Color-Replacementd size mark on toe for easy match-up after laundering