Zoo Med Reef Sun 50/50 Mini Compact Fluorescent Lamp has a 50/50 combination of 6500K trichromatic daylight phosphor and actinic 420 phosphor in the same lamp. It provides high intensity full spectrum illumination that is strong in the short wavelength blue region essential for photosynthetic corals and invertebrates. Zoo Med Reef Sun 50/50 Lamp is ideal for all marine aquariums, reef aquariums, African Cichlids, and Discus Fish. Fits standard medium base. Size: 5" long. 10 watts.