Smooth heel socks. These socks are made of neoprene submersible material that is highly elastic and flexible, so they have good elasticity and fit perfectly. Excellent breathability and moisture absorption for a smooth and non-stuffy feel. Size: L 4.3 x 4.7 inches (11 x 12 cm); Contents: Set of 3 pairs with instruction manual (English language not guaranteed) All products are inspected in Japan and are ready to respond to any product defects.