Description: Product: This is an essential physics experimental equipment kits, designed to help students learn the frictional force of objects, making it a great educational tool for elementary physics and mechanicsMaterial: Newton's motion and force experiment instrument is made of sturdy metal material, ensuring long term use and resistance to wear and tearEducational Tool: This physical mechanics experiment apparatus serves as an useful educational tool for students to understand the principles of mechanics in a hands-on mannerPackage Includes: Each package contains a complete set of the Newton's Motion and Force Experiment Instrument, making it compact enough for easy storage and transportWide Application: Great for home, school use. Also ideal Birthday and Christmas gift for kids, children in elementary and middle school, can enjoy DIY experiments fun while learning basic physical Specification: Material: Metal Size Chart: 40cm/15.75inch 55cm/21.65inch Package Includes: 1 SetPhysical Motion and Frictional Force ExperimentEquipment 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.