The Exo Terra Reptile UVB100 emits optimal amounts of UVB, similar to the conditions found in shady environments like rainforests or other tropical areas. The reptiles native to these habitats receive moderate amounts of UV radiation due to climatic conditions, such as relatively high humidity and weather changes. This prevents unfiltered sunlight from directly hitting the basking reptiles. The optimal vitamin D3 benefit index ensures vitamin D3 photosynthesis, which contributes to calcium absorption and protects against bone softening.