About the far infrared sock: The far infrared sock is also called negative ion sock, a kind of health product base on far infrared fabric combined with spandex. It can constantly produce negative ion and biology wave for human beings. They all have thermo-effect of infrared radiation to human body. They can activate biological molecules and water molecules in human body, promote blood circulation and metabolism, and improve immunity. Structure: External material: 100% cotton Internal material: far infrared fabric combined with spandex Component: tourmaline powder, far infrared fabric, spandex Specification: average size Color: white, pink, black, grey,red Function: 1. The far infrared and negative ion can perfect the foot blood circulation, and neutralize acids come from sweat. 2. Inhibits bacterial growth, Indomethacin antipruritic. 3. Reduce pain of foot, and helpful for cure panneuritis epidemica, pernio, and abdominal pain.