This bulb is made by Jalli lighting which is actually very reputable and known for putting out solid products. This bulb more closely relates to ATI's 450nm blue bulb- strong in blue hues, but lacks in the true 420nm actinic range which is violet/blue in color. Corals wont flouresce as great under a 420nm bulb... other than that- its a very good price and amazingly bright lamp- def worth it if your looking to balance out yellow lights in your tank!