WOW Technology, SmartWool Fit System with arch and ankle support. Two sizes of stripes combine for a fun and stylish knee sock. * Women"s sizes Small (shoe size 4-6.5) Medium (shoe size 7-9.5) Large (shoe size 10-12.5) NOTE Women"s size Small fits Youth shoe size 2-4.7 * 74% Wool, 25% Nylon, 1% Elastane. Washer and Dryer Friendly! * Cushioned sole, knee high height.