Back on Track products have ceramic powder in their unique Welltex textile products. The ceramic reflects back body warmth as a far infrared wave that effectively stimulates blood circulation in the body. Back on Track products have ceramic powder in their unique Welltex textile products. The ceramic reflects back body warmth as a far infrared wave that effectively stimulates blood circulation in the body. Size: 11". https://botcanada.com/ sizing charts can be found https://botcanada.com/sizing-charts/