Zilla Rapid Sense DecorReptiles need UVA to regulate their day night activities and UVB to help synthesize vitamin D3 and maintain healthy calcium levels. Without enough UVB, they're in danger of developing nutritional diseases that can be fatal. The Zilla Rapid Sense UV Detecting Dcor lets you easily ensure your pet reptile receives the proper UVB levels for optimal health. When exposed to light, the Rapid Sense Decor indicator changes color, allowing you to check the UVB