Powerful, Actinic 03 Blue T5 HIGH OUTPUT fluorescent lamp ideal for supplementation in reef aquaria and coral enhancement. 100% blue phosphor that peaks at 420nm. Provides light vital to healthy growth os photosynthetic corals. Simulates the blue hue of deep water. Universally sized and compatible with most T5 HO lamp systems. Low profile, space saving design. Use with high power electronic ballasts for efficiency and extended service life.