I have become a big user of Bankers Boxes over the last few years. I use them for storage purposes and to transport items from place to place. These "box shells" make it easier to get to boxes that are stored on top of each other. Only issue I have with this item is the price. With tax, these box shells cost about $8/shell. I guess the price is not that bad, since these shells are well built and most likely will last forever if you take care of them. On the other hand, you are paying quite a bit for basically cardboard and a little metal.
I also want to mention that Fellowes, the company that makes this item, has great customer service. One of the shells I received was defective, and just by making a call to the company they went ahead and sent me a replacement. I love when companies stand behind their products.