The walls of the cylinder in one half of the cube are a lot longer than the other half. One day I thought this might be a good place to stash a little paper money. Or a piece of paper with passwords on it for anyone who writes them down (not me). Bills will only fit if you fold them in half before you roll them up, or you fold them the other way. I also tried some coins to see what would fit inside it. Quarters are just a little bit too big but nickels fit inside it. A 12 gauge shotgun shell will fit the diameter but a 2 3/4" shell is about 1/4" too long. A mini-shell would fit for sure, if that helps anyone get a sense of how big it is. Paper money or paper wouldn't rattle if anyone picked it up and shook it. That's why I thought it might be okay as a stash, unless some curious person steals it.