Kids get an introduction to mechanical engineering as they build 8 motorized robotic animals and make them work—developing fine motor, visual-spatial and reasoning skills as they go! The kit guides kids through the building process and invites them to follow along with a super-engaging story, helping them create a robotic bear, crab, narwhal and more. Kit includes 146 building pieces and a full-color 32-page storybook manual with illustrated step-by-step instructions. Largest piece measures 3 5/8" in length. Requires 2 “AA” batteries (not included).