They're only normal footlockers, to my knowledge. You're not allowed to take much with you to basic, so you don't have all of your worldly possessions (unless you're a neko). Think of it like a big box, bottom of it is completely open, no partitions, and then there's a shelf that goes on top of that bottom compartment you can lift out to get at the bottom that's partitioned into two parts.
If I wasn't mid-move, I could give you guys a picture from irl, but... Think like a hidden bottom, except it's much more loose and obvious then that. And the top part is only about 3 inches deep, out of a total foot and a half or so.
So, think about 4' wide by 1'6"~ tall by 2' deep, with a 3-4" tray on the top of the chest.