The Zilla Mini Day White Halogen Bulb for Reptile Terrariums is an energy-saving halogen replacement bulb for your terrarium’s heating fixtures. It can be used with the Zilla Halogen Mini Dome, Heat & UVB Basking Fixture and Mini Heat & UVB Fixture. This tiny bulb provides spot heating and white light to keep your reptiles warm and comfortable. It’s 250% more efficient than incandescent bulbs, plus it’s more compact, so it takes up less space on the top of your terrarium.