"The Ideal Concept": 2 - Metal Halide bulbs (See Option to Upgrade your Metal Halide and ballast to a higher Kelvin (Whiter & Bluer) and/or higher wattage (Brighter). For tank height 18" to 36" use MH 175W / 24" to 36" use MH 250W / 24" to 60" use MH 400W), 2 - 55W 7100K Blue PC Compact Fluorescent bulbs, 2 - 55W PC Compact 6700K, 2 - 4" fans, High Quality electro-white reflector, Black Aluminum canopy, Dimensions: L48"xW11.5"xH6.5" This is the BEST system we have to offer. It is a 2-in-1 setup; you can choose to run metal halides and/or compact fluorescent tubes.