These halogen lamps are broad spectrum and emit more natural light and higher amounts of UVA which contributes to the well being of reptiles. The front glass is diffused to spread light. They also give more heat and light and reduce ambient air temperature. This makes it easier to create the heat gradient in the vivarium. Halogen lamps have a longer life than the filament types; and use up to 15% less power. Size: 60mm (2.5") diameter, 80mm (3.25") length.