In the wild, your reptile receives visible light from the sun, in both visible light and infrared spectrums so it can see, as well as warm up to thermos-regulate for good health. Combined heat, light and UVB in one bulb.
eBay
The lamp also projects UVB up to several feet from the lamp's surface and is also ideal for large terrariums or bird aviaries. Features include quality nickel plated threads to prevent against corrosion, and also a 6 month warranty!
eBay