Highly attractive Glo T5 HO (High Output) Systems were developed for both marine and freshwater systems to direct maximum lighting to your aquarium. Due to the compact diameter of the T5 HO bulbs, up to two of these powerful bulbs can now be housed in the same space that one T8 or T10 requires, providing substantially greater light levels and reducing space requirements at once. The combination of the space saving design, energy efficiency and easy installation make the T5 HO System ideal for aquarists of all levels from the novice to the hobbyist. This 36″ Glo T5 HO Lighting System features a 39 watt high output format and a double light configuration. Integrated extension brackets adapt to a range of aquarium lengths (35 to 52 inches).