Zilla UVB Fluorescent Coil BulbZilla Desert 50 Bulb provides a full dosage of UVB along with essential UVA light Ideal for desert dwelling reptiles that require UVB UVA lighting Provides UVB light rays which are required for many reptiles to metabolize essential calcium Full spectrum lighting enhances natural colors of the animal and environment Energy efficient bulb which lowers energy costs Coil bulb design fits most standard incandescent bulb sockets