The Reptile Systems D3 6% UVB lamps are designed specifically for rainforest dwelling species such as Chameleons, Water Dragons and Crested Geckos. These lamps help your reptile generate vitamin D3 when they bask under it, allowing them to absorb the calcium in their diet and use it to build strong skeletons. This is an extremely important part of reptile keeping and without D3 UV and calcium, your reptile can develop problems like Metabolic Bone Disease.