This is a fold that turns out to be a box with a small hole into the top. Once you have completed the fold you blow into the hole at the top and it inflates the fold into a box shape. Because of this inflation it is also called "The Origami balloon". But you can also fill it with water and throw it which makes it the water bomb. Another interesting use of this is that you can put a fly in it and the shape and paper will amplify the buzzing of the fly.