Let’s take a Collapsible Container with the dimensions 48” X 45” X 34”. The height when the container is open is 34” but when the walls collapse the height is 12.5”. With a collapsed height of 12.5” another collapsed 48” X 45” X 34” can be stacked on that container and the height will be 25”. For storage purposes you will be able to stack at least 2 collapsed containers using less space than the open container. If you for example, had a rigid container that was 48” X 45” X 34” you would not be able to economize on storage if your container was not being used.