Soft-stretch, elastic band top that gently conforms to your legSmall: 35-38 (US Women's 4-7.5) Original Birkenstock seal stands for premium qualityMedium: 39-42 (US Women's 8-11.5, US Men's 6-9.5) High-end, long-staple cotton blends for a perfect fitLarge: 43-46 (US Men's 10-13.5) Enhanced toe and heel zones for long-lasting durability Ultra-smooth toe seam for all-day comfort in sandals, clogs and all other shoes Roma Birkenstock Roma Socks keep your feet cozy no matter what Birkenstock footwear you are wearing!