This is a CS135 series skimmer that has been used for about 4 months. Rated safely for 135 gallons, though I was using it on a 180 without any problems whatsoever. The comparative rating of the skimmer is 300 gallons on the website, but I think they're using the rating used by ASM and a few brands (over-rating the skimmer). Basically is puts out 660 lph of air, which is the most limiting factor in skimmer efficiency.
I'm getting rid of it because I've upgraded to a 250 due to a recent tank upgrade.
Here's the specs on it:
http://www.euro-reef.com/csrs135specs.shtml
And here's some info on the CS line and what makes them different:
http://www.euro-reef.com/products-csseries.shtml
This skimmer really hauls. Super rugged build quality and quiet operation, this is your chance at a deal on the real thing.
Retails for over $700 with taxes, I'm asking $350 firm.