Warm Things Down Booties cotton 300 thread count, 100% cotton sateen fabric is soft and breathable for exceptional comfort 550 fill power white down traps your body heat to keep your feet warm and cozy without overheating Enjoy the luxury of the finest down comforter in slippers - warm, lightweight and breathable Women's shoe sizes: XS (5-6) S (7-8) M (9-10) L (11-12) Men's shoe sizes: S (5-6) M (7-8) L (9-10)