Women's and Men's Non-Slip Non-Skid Organic Cotton Grip Socks, Largest Color Selection! Organic Cotton! Organic Cotton Sock with Non-Slip, Cushioned Reinforced Sole. Great for Low-Impact Exercises such as Yoga or Pilates, or Simply Lounging with the Safety of a Non-Slip Sock! Sizing: Small = Women's 4-6, Medium = Women's 6.5-9.5 & Men's 5-8.5, Large = Women's 10-13 & Men's 9-12.5 Great Hygienic Solution for Travel! Wear in the Plane, the Hotel, Train or Automobile! Keep Germs Away! The Original TractionSocks!