It is the most value set on Amazon in terms of versatility and number of pieces. If you don't love it for any reason, you can return it for a full refund. Our unique engineering set helps kids develop mental muscles through interactive play! Supports logical thinking, cognitive system development and reasoning. Perfect for preschool, kindergarten classrooms, and up. Promotes STEM Learning - This teacher-recommended, innovative play set provides your kids with a solid foundation for in-demand skills! From science and physics to math and geometry, our educational toys encourage kids to build their critical thinking and problem solving abilities as well as their teamwork and social skills. Includes Builder'S Guide - A full-color builder's guide with 42 ideas for beginner, intermediate and advanced builders ensures creativity, success and incredible geometrical configurations! Our toys and storage containers are lead, BPA and phthalate-free. For a quick, hassle-free clean up, simply rinse the toys under warm water.