Right, but take those ratings with a grain of salt. The Eshoppes rep let me borrow one of them for my display tank at MACNA when it was in Atlantic City. I wouldn't use that on anything larger than maybe 40 gallons. It's comparable to the Coralife Super Skimmer 65, another skimmer that's loosely rated.
Generally, you want something rated for 1.5 to 2 x your total system volume.