Kids First: Intro to GearsGears make things move! Join Ty and Karlie the young engineers featured in the other Kids First early engineering kits to build four awesome geared machines and learn all about how gears work. This introductory mechanical engineering kit for kids ages three and up features 61 durable, reusable, easy to handle pieces, ensuring long lasting fun and exploration. Intro to Gears is a fun and engaging way to explore the many amazing things gears can do.