As skills develop, kids can build their creativity and imagination even further with Pop-Onz PRO - an extension of the system that allows preschoolers to easily build more sophisticated, appealing and familiar structures using blocks, accessories and figures that appeal to the older child. Unique hinged wall panels, large Pop-Onz building surfaces and colorful roof blocks make building familiar structures in many different ways as easy as 1-2-3! Both sets are packed in a vinyl bag for storage and take-along play. All blocks and pieces in the Pop-Onz Pro line work together for even more building fun!