I bought this for over $3,100. You can see similar ones
here:
48x15x31 is the actual size I measured, but they sell it as a 55x15x31. You can change how it is configured a little by rotating the pieces (they are connected with dowels).
I have used it for about a year, but it still looks great. I would like 50% what I paid for it, but I am willing to accept offers. I switched to rock and real corals. So I probably won't use it again. It was the perfect size for my tank (5'x3'x3'). You can take the arch off, and make it shorter and longer, but you would probably want to put something on the flat tops.... If you have questions, ask me and I can take more pictures, measurements, etc.