This isn't a wad of that gray stuff that ruins the loaf before you're even two-thirds done with it (no, I'm not bitter), but rather a metal device that you can put bread into before baking it so that it comes out in a perfect bread-roll shape.

I guess you could also use it as the casing for an improvised explosive device, if you had the right kind of fire for it, but I don't know what the origin of that fire would be.