We ordered this fort building set over the others because the connecting rods were slightly stronger than the others. When squeezed, the ends snap into the perforated balls - they won't come out unless squeezed again, so the designs are fairly stable. Our kids aged two and five enjoy this set - they build simple fortresses out of parts and it's an activity that both can play and enjoy at the same time. The instructions are simple and the building guide contains four basic concepts that can be built with just one set.