Zilla UVB Fluorescent Desert Coil Bulb, 20 Watt (2 Pack) Pack of Two 20 Watt Zilla UVB Fluorescent Desert Coil Bulb Desert Series 50 coil bulb is 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 (replace every 12 months to ensure proper UVB levels)