These are a couple unit Origami folds that I have folded from models in books. The largest is composed of 30 units, all folded the in the same manner. These units can be combined into other forms like a 60 unit module. The two smaller spheres are made with different units. Each of these has 12 units. Using the same units you can make a variety of shapes. Using 6 units you can make a box. Many other forms are possible. This particular unit is one of the most sturdy units for construction. When you push on the outside of the spheres, once combined, they tighten almost like when you press on the outside of a snow ball. They hold together so tightly that you can play catch with them. The other units usually need a tiny dab of glue to keep them together for a more permanent display. There are many different units you can fold to make a wide variety of forms. Why not check out some of the unit Origami books at your library and give it a try?