It's a CPR refugium.
You can get them here:
CPR AquaFuge Hang-on Back aquarium refugium / Gina's Aquarium Supply
CPR actually makes several sizes. You can get specs at the CPR site, here:
CPR AQUATIC, INC: Products
I started out with the Aquafuge 2. It's 19" long and does not have a built in skimmer.
I bought an in-tank skimmer that sucked and blew bubbles all over my tank.
So, I bought the Aquafuge PS large model thats 23" long and has the built in skimmer. It totally kicks butt. I only open the air valve to let it skim at night. I want my corals to eat during the day. I skim about 8-10hrs per night. I shut the bubbles off when I get up around 6:30am.
If you have 24" of room on your tank--DEFINITELY get the one with a built in skimmer. I think they make a smaller one thats only 19" long and has a built in skimmer. I have a 19" model without a skimmer. But, now that I see how they built it in, I might just slap a couple pieces of plexiglass in mine and build a skimmer into it.
My tank is an All Glass thats 24" wide. The large 24" CPR just BARELY fits on a tank that size. I mean
BARELY. It's tight, but it fits. You'll have to turn the intake tube out a bit to make the powerhead fit without hitting the side of the tank. But it's a threaded connection, so ya just twist it a little tighter and slap the powerhead on.
Ginas Aquarium supply also sells the legs/stands for the CPR lights that fit on top of the refugium. I bought the 18" light with 24w light.
When you get to the refugium page on Ginas, scroll down to see the leg kits. They sell the lights too.
The 18" light with 24w daylight 10,000K is CPRL 1624
The stands for the medium 19" refugium are AFSTND
The stands for the 24" refugium are PSSTND, but I used my old ones when I upgraded my refugium. The old ones work, but they are a little loose. You'd have to see it to understand. It makes no difference which ones you use on the larger refugium. The larger refugium is actually about 1/2" slimmer than the smaller 19" fuge. So, when you use the ASSTND legs on the larger fuge, they can slide back and forth a little bit. They don't fall off though. It's designed so that it won't fall off.
The large 36" light CPRL2436 is for the under tank refugium. It's 36w.