Giesemann AquaBlue Azure 39W 36" T5 HO Lamp 34 inches from end of pin to end of pin (for 36 inch fixtures/retrofits) The Giesemann AquaBlue Azure is a turquoise blue a 16-17000K lamp developed for reef aquariums providing higher PAR to enhance the colors and growth of corals whilst producing a rich turquoise blue for optimum aesthetics. 39W T5 HO Lamp. Will work in any T5 fixture, as long as you are using bulbs of the same wattage and length as those currently in your fixture Recommended for marine and reef aquariums Promotes coral growth by reinforcing the preferred range of zooxanthellae in the blue spectrum