I was going to use these two together to upgrade to 8 bulb by putting them side by side, however, I was able to find an 8 bulb fixture so I don't have to rig these together. They are 1.5 years old, which comes with working bulbs but they are probably end of life if you are looking for maximum par. Two separate ATI Dimmable 48" 4x54w T5 fixtures. They are dimmable and programmable on it's own built-in controller on the fixture. The guy previously used it on an 8 foot mixed reef with good results. $300 each firm located in San Jose.