Giesemann AquaBlue Coral 39W 36" T5 HO Lamp 34 inches from end of pin to end of pin (for 36 inch fixtures/retrofits) The Giesemann AquaBlue Coral lamp is the ultimate blue/white light spectrum ( Special 70:30 combination of 6000K and 22000K). 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 reef aquariums Reinforcement of all colors in fish and corals