Learning and fun go hand in hand with this interlocking gear building set. The set comes with 81 gear pieces in a variety of sizes and colors, and has a battery operated motorized gear (battery not included) that creates movement in the structures your little one builds. This set is a wonderful STEM (science, technology, engineering, math) learning toy that teaches kids how to construct things and how parts move in connection with one another. Its also a visual and tactile way to develop other learning skills such as counting, sorting, matching and thinking. Your little girl or boy will enjoy hours of imaginative and creative play with this toy set!Detail:Multicolor81 pieces in different sizes, colors and shapesSTEM learningMoveable gear requires one AA battery to operate (battery not included)For ages 3 and up