Gears Toys: Gear Transmission DIY Toy Science Experiment Kit for Children, STEM Educational Tool Material: This gear transmission toy is made of pp ensuring durability and longevity while providing a safe play experience for your children Educational Value: This STEM based learning tool is designed to stimulate children's interest in science and technology through hands on experiments, promoting their problem solving skills, creativity, and cognitive development Multifunctional: Educational learning toy for school projects, DIY science, mentary school students, kids, children Early Educational Toys: These DIY science kits help children solid foundation , technology, at an early age. Nice birthday holiday gifts for boys girls children, etc Specification: Material: PP Size Chart: 10.3x9cm/4.06x3.54inch Package Includes: 1 SetGear Transmission DIY Toy Note: 1.This is not infant toy , please take away from children to avoid eating.2.Please allow slightly errors 1-2cm differences due to manual measurement.