The BioBelt has 8 types of semi precious crystal gemstones: Amethyst, Green Jade, Black Tourmaline, Topaz, Tiger Eye, Citrine, Elvan and Quartz. The warmth directly speeds up digestive enzymes, which produces a cascade of other effects. Digestion and metabolism are improved, and serotonin levels increase, leading to satiety and reduction of appetite. The BioBelt's smaller size and velcro belt allow it to be the most versatile BioMat product. It can be used on many parts of the body that are harder to reach with the larger mats. It works in combination with those mats. The active crystal portion is 8″x18″x1″.