There are many types of materials that emit far infrared sauna heat including ceramic, steel, incoloy rods, and carbon. We chose organic carbon due to the proven effectiveness and efficiency of carbon. The human body consists mostly of carbon, so the frequency at which it receives far infrared sauna heat is perfectly compatible with the Solocarbon® heater. The #1 selling portable sauna in the world, the Sunlight Solo™System, utilizes Solocarbon® heating technology and has been proven for years to emit nearly perfect far-infrared heat.