They are 21" Nova T5s. The same as the following but 21" instead of 36":
http://www.marineandreef.com/ProductDetails.asp?ProductCode=RCU01105&click=2
I have two daylight and two actinic. They fit right inside the plastic light "guard" that covers the stock PCs. I had to cut out small openings in the plastic light guard for the wires to come out of it. I also am running a set of LEDs- four strips with 9 lights per strip-Daylight. I will be adding two or three more sets of four strips of LEDs as well. With the T5s in the hood, I can keep just about any SPS while keeping the classic all in one biocube look.
Pic:
I will be adding more LEDs between the fans on the reflector, and on the front hinged opening on the hood.