18 months & up. The STEM building toy system for toddlers, Grippies® Builders combines tactile exploration, magnetic play and an introduction to the basic principles of engineering and geometry. Grippies® unique, magnetic rod and ball configuration provide a secure, frustration-free set of construction options as children first discover the joy of building. Unique in concept and design, Grippies® provide a fun, safe and exploratory experience for toddlers. These sets feature four soft matte textures in exciting bright colors. Compatible with other Grippies® sets.