So about two thirds of the central cavity is filled with water, and that makes an aqueous environment. But why is that important? Well, that's important because these K plus ions, the potassium ions, actually interact with the water molecules to form a more stable structure. And this interaction creates something known as the Salvation Cage or the Salvation Shell. So essentially, the full positive charge on these potassium ions interacts with the negatively or the partially negative charges on the oxygen atoms of the water molecules. And so the water molecules essentially orient themselves around the potassium to form a cage of water molecules we call the Salvation Cage.