AB Bulbs are widely regarded as among the highest quality aquarium bulbs in the world. These premium HQI bulbs have been consistent favorites for their true-to-life color and extraordinary longevity. In two years time, these bulbs lose less than 25% of their total output without a dramatic shift in color. AB bulbs are available in mogul (screw base) pulse-start formats, in the 10K color as listed below, and as double-ended HQIs in 13,000K and 20,000K color spectra.