(4 Pack) Exo Terra Solar-Glo High Intensity Self-Ballasted Uv/Heat Mercury Vapor Lamp, 125 Watt Pack of 4 Exo Terra Solar-Glo High Intensity Self-Ballasted Uv/Heat Mercury Vapor Lamps, 125-Watt 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