●Main Material: Cotton ●Function: Warm, wear-resisting, anti-skid ●The interior is fluffy microfiber. This is an essential item for winter that will keep your cold feet warm in winter ●Non-skid bottom for safety ●Soft type that bends to match your feet, making it easy to walk and quiet. This is a washable type with a very gentle knit material that can be washed if it gets dirty