Thorlo's Ankle Length Lite Walking Sock Offers the Most Padding in a Lightweight Construction. There's Medium Density Padding in the Heel and the Ball of the Foot For Extra Cushion and Lightweight Padding in the Arch and Across the Top of the Foot for Extra Protection and a Better Fit. A Special Blend of 72% Coolmax®, 26% Nylon & 2% Spandex Fibers Provides The Ulitmate in Moisture Wicking For All Day Comfort. (Sock Size 9 = Womens Shoe Size 5-6.5, Sock Size 10 = Womens Shoe Size 7-9, Sock Size 11 = Womens Shoe Size 9.5-11.5