MACHINE WASHABLE: Use a mild detergent in warm water at around 30 degrees C(86 degrees F) for washing. Do not use tumble dry. Do not use bleach. PILE KNITTING: The toe and heel are comfortable because they knitted by pile knitting. Pile knitting is a knitting method often used for towels, and it is soft, elastic and comfortable. COVERS HEEL WIDELY: It is hard to slip off because the heel is covered widely. TAPER SHAPE: It fits very well to the ankle because it is a three-dimensional shape that widens from the ankle to the opening. ARCH SUPPORTER: You may feel that your feet are less tired by supporting the arch. FITS SHOE SIZE: 25-27cm JP, approx. 8-10 US Women / 7-9 US Men. PACKAGE INCLUDE : 3 pairs. Machine Wash. Imported. Polyester/Cotton/Nylon/Polyurethane.