This T8 fluorescent bulb is built for reptile terrariums and delivers a combination of UVB and UVA light to help reptiles process dietary calcium and maintain healthy bone and skin. It is intended to be installed in a Zilla T8 strip light fixture positioned above the terrarium, oriented so the light reaches the baskng and activity areas of the enclosure. The bulb is offered in more than one UVB intensity level so keepers can select the output appropriate for the type of reptile being housed. Full spectrum output also helps bring out natural coloration in both the animal and its surroundings. Bulbs should be replaced on a regular schedule since UVB output diminishes with use even though visible light remains. No assembly is required beyond fitting the bulb into a compatible fixture, and the glass tube should be handled carefully to avoid breakage.