they are organizer cubes, you can get then at costco, target, staples, superstore, wal-mart... their are differnt brands of them, a common one used is neat idea cubes, where I live only one brand is avaliable, and they are just called organizer cubes lol you can use the conectters to just make like a square or rectangle, but you can use zip ties to make then virtually any shape you want. the base of the cage is generally coroplast, which you can get at any sign store, and at some home building stores.