Exo Terra Reptile UVB 100 Tube 18W 24in PT2386 T8 Fluorescent Lamp

The ET Reptile UVB 100 Tube 18W 24in (PT2386) is a T8 fluorescent UVB lamp designed for tropical and rainforest reptiles that experience moderate, filtered ultraviolet radiation in the wild. If you keep species from humid, shaded, or seasonally overcast environments — think rainforest geckos, chameleons, or tropical forest skinks — this tube delivers the UVB intensity that mirrors those conditions without overpowering animals not adapted to intense, open-basking UV exposure.

UVB Output and D3 Synthesis

The UVB 100 is calibrated to produce UVB levels consistent with shaded tropical habitats, where cloud cover, canopy, and high humidity reduce the amount of unfiltered UV reaching the reptile. This moderate UVB output supports a proven Vitamin D3 yield index, enabling D3 photosynthesis through the skin. Adequate D3 production is essential for calcium metabolism — without it, reptiles are at serious risk of metabolic bone disease over time.

Sizing and Vivarium Compatibility

At 24 inches in length, this 18W T8 tube is well suited to medium-format vivariums. The longer format also means it can span across multiple smaller terrariums positioned side by side, making it a practical choice for keepers running several setups in a rack or shelf system.

Packaging and Reference Data

The packaging is a useful reference tool in its own right, not just retail wrapping. It includes a full spectral graph, a UV spectral graph, UVB output figures at varying distances, photosynthesis data, Ferguson Zone placement guidance, and the Reptile Bulb Rating System — giving you the information you need to position the tube correctly and confirm it suits your species.

For keepers who take lighting seriously, the ET Reptile UVB 100 Tube 18W 24in gives you measurable, species-appropriate UVB in a standard T8 format, backed by the data to use it with confidence.