Its very very rigid, not styrofoam, you would need a sharp hacksaw to cut it...you can choose different styles,
back looks like this
here's a link on ebay.
http://www.ebay.com/sch/i.html?_trksid=p5197.m570.l1311&_nkw=3d+aquarium+background&_sacat=0
Thanks for the info and link eminence. I'm second guessing if i should buy it now. I got two overflows in my 125gal and I can't figure out how to install without removing the overflows or leaving a huge gap. I've seen another members setup and I believe he took the overflows out and left the pipes there.
I went on ebay and saw the listing for the same background. Its definitely for both pieces. $113 shipped. I thought the shipping would be cheaper since the seller and I are both in FL.
http://www.ebay.com/itm/3D-AQUARIUM-BACKGROUND-/280852940196?pt=LH_DefaultDomain_0&hash=item416423c5a4
