Super Actinic R 420nm T5 Fluorescent Aquarium Lamps by UV Lighting Co. The most widely used aquarium lamp on the market for over 20yrs. The 100% Blue spectrum, which peaks at 420nm, stimulates photosynthesis and coral fluorescence. Great for all marine enhancement. URI has established itself as the hobby favorite with their popular VHO lamps and now they're continuing this with their T5 line. T5 lamps are unmatched in their output and intensity due their reflective possibilities. Their small diameter (compared to other fluorescent lamps) allows manufactures to create parabolic reflectors that are extremely efficient. These lamps are the future of fluorescent technology. Whether you use them as supplementation with metal halide or stand alone they are sure to impress. The URI super actinic R is the most widely used aquarium lamp on the market. 100% blue spectrum. The URI super actinic is great for reef applications and coral enhancement. *Important Shipping Information: Minimum order of 2 (two) T5 lamps, (Mix & Match), to qualify for our standard shipping fees.