The ReptiSun® NANO UVB bulb is perfect for tropical species with low UVB requirements. UVB light helps prevent or eliminate Metabolic Bone Disease in most commonly kept reptile species. The ReptiSun NANO also emits UVA light that can improve feeding response, breeding behavior, and daytime activity levels. This bulb is suitable for replicating daylight in captive reptile habitats. These bulbs offer consistent UVB and UVA output for up to 12 months! the ReptiSun® NANO UVB bulb is ideal for use in 10-gallon terrariums or smaller. The bulb is designed to fit ZOO MED'S NANO DOME or the ZOO MED NANO COMBO DOME.