Pet Exo Terra Solar-Glo High Intensity Self-Ballasted Uv/Heat Mercury Vapor Lamp - 125-Watt. Lamp Supply Store/Shop Self-ballasted mercury vapor bulb Helps prevent metabolic bone disease Provides the benefits of natural sunlight Optimal levels of UVB, UVA, visual light and heat in one bulb Increased UVB penetration distance, + 12 inches