The Exo Terra Repti Glo 10.0 Compact Desert Terrarium Lamp has a very high UVB output similar to that associated with desert environments. Desert locations receive more direct sunlight than any otherbecause of fewer clouds, less air humidity and no plants or trees to provide shade. Therefore desert reptiles are more exposed to UV radiation than any other type of reptile. This bulb can also be used on screened terrariums or terrariums with dense screen covers to ensure UVB penetration. Dense screens can filter out up to 50% of the UVB rays. Fluorescent bulbs lose their UV radiation and approximately 50% of their lighting output quality within one year. Ideal for all desert dwelling reptiles, the Exo Terra Repti Glo 10.0 Compact Desert Terrarium Lamp provides the necessary UVB ray for optimal calcium metabolism Recommended in combination with Repti Glo 2.0 Compact Full Spectrum Terrarium Lamp for a higher visual light output.