The Exo Terra Reptile UVB200 emits the ideal UVB spectrum for optimal Vitamin D3 photosynthesis. The Reptile UVB200 Bulb is especially designed to simulate conditions for reptiles with very high UV requirements, like diurnal reptiles from desert environments. These areas receive direct unfiltered sunlight with high levels of UVB. The significantly high Vitamin D3 yield index results in increased vitamin D3 photosynthesis to aid calcium absorption and prevent metabolic diseases. The extended UVB penetration makes this bulb the ideal choice for taller terrariums or terrariums with denser screens. Key Features : For reptiles with very high UV requirements Helps prevent metabolic bone disease Ideal for desert set-ups or taller terrariums Very high D3 Yield Index Increased Vitamin D3 photosynthesis Maximizes calcium absorption Enhanced UVB penetration distance Combine with Natural Light or Reptile Vision for optimal visual light output Others available : Reptile UVB200 High Output UVB Bulb 26W (PT2340),