Techno Kids Stack & Spin Gears lets kids build their own toy! Simply put together the base plates in any configuration and add on the gears. You will make an amazing kid-powered machine! From interlocking base plates and rotating gears to a large playland construction set, Techno Kids Stack & Spin sets are perfect for an open-ended exploration of simple mechanics. These products align with and support STEM (Science, Technology, Engineering and Math standards). Recommended for ages 2+ years.