I purchased these a year ago. I've worn them a few times indoors. There are a few scratches on the sides and toes. Made with natural wood (Aizu Paulownia), the finish uses plant-based oil. The thong is designed to fit the human body for easy wear. Walking in them every day is said to strengthen the toes, help form the arches of the feet, prevent bunions, and improve blood circulation. It is also said that they help you engage your core, eliminate floating toes, align your ears over your shoulders, and improve your posture.