Exo Terra Reptile UVB 100 Tropical Terrarium Bulb Exo Terra Reptile UVB 100 Tropical Terrarium Bulb – New & also improved range of UVB linear tubes replaces the popular Repti Glo range. Replacing the ET Repti Glo 5.0 T8 tubes the new ET Reptile UVB 100 T8 tubes do away with the percentage terminology of linear tubes. Instead focuses on the average UVB output, based on a basking distance of 10cm from the lamp. The Exo Terra Reptile UVB100 emits optimal levels of UVB. This also similar to that of shady environments such as rain forests or also other tropical locations. Reptiles living in these habitats receive moderate UV radiation. This due to climatological conditions that prevent unfiltered sunlight from reaching the reptile’s basking site. The optimal Vitamin D3 yield index ensures vitamin D3 photosynthesis. This to aid calcium absorption and also prevent metabolic diseases. No longer should you have to rely on the 5.0 principle which only vaguely indicates the UVB output of the lamp ranging between 280 – 320nm. The 100 terminology focusing on the 290 – 310nm wavelength which is the range responsible for vitamin D3 synthesis. Combined with Exo Terra’s new UVB lighting app the right lighting requirement is no longer an educated guess. You can actually put the onus on the keeper also allowing for better accuracy between keeper and retailer. All of the new ET lamps have also been designed for maximum vitamin D3 photosynthesis by concentrating the UVB output near the 294nm wavelength (the wavelength responsible for peak D3 production). The packaging also includes all necessary information for shoppers to make the right choice. Includes, Full Spectral Graph, UV Spectral Graph, Reptile Bulb Rating System and distance related information like; UVB output – Photosynthesis – Ferguson Zones and Exo Terra Reptile UVB CHart. The longer sizes can be placed on multiple terrariums.