Coralife Power Compact Fluorescent Aquarium Fixtures : A complete hood system, ready to be placed over your tank. Available in sinlge double and four lamp configuration. Coralife power compact hoods are avaialable with freshwater and saltwater lamp configuration. these powerful compact fluorescent units are high quality! Built-in Electronic Ballast. 2 fans built into this unit! The fans are positioned on the top of the fixture (blowing upward), not on the sides. Please note: there are 4 holes on the fixture, but only 2 have fans in them, the other 2 have fan screens only. Sleek Aluminum Housing. Highly-Polished Reflector. Acrylic Lens Cover. On/Off Switch. The optional mounting legs will raise the unit 1 1/2" high over the top of the tank, and the legs can expand to fit 2.5" longer than the unit itself. In other words, this 36" unit can be mounted on a 38.5" long tank, with the mounting legs installed. The mounting legs can fit tanks smaller than the unit's length, since they mount in a channel that runs the entire length of the fixture.