Vitalsox Performance Bacteria & Fungal Resistant Crew Socks 75% Silver Drystat 15% Lycra 10% Nylon Imported DRYSTAT infused with silver for a natural bacteria resistant, wicking and quick drying material. SIZE CHART: Small (Women's 5-8, Men's 4-7), Medium (Women's 8-10, Men's 7-9), Large (Women's 10-12, Men's 9-11), X-Large (Men's 11-14). Due to the stretchability of the sock, if your shoe size is between sizes, choose the smaller. FUNCTION arch and gentle plantar ligament support, part of your long term foot care PREWASHED using a "chemical free" softener, each sock is inspected by hand for quality and function. QUALITY Every product is made to strict specifications in our Italy factory never outsourced to the lowest bidder.