Features: Package includes: 1Piece Dynamometer, 6Pcs 20g Hook Weight with Stand, 1Piece Cotton Strings, 1Piece Multifunctional Holder Base, 1Piece Wheeled Car. Unlock the mysteries of mechanics and friction experiment with our Mechanics Friction Experiment Set, must have physics teaching aid to explore and understand the fundamental principles of physics mechanics and friction. Very suitable for student, children aged 8 ＋. Develop their ability of hand on, and improve train observation, thinking and analytical skills. A fun way to teaching and learning to mechanical principle and the conservation of energy. Whether in school physics lab, homeschooling, this science physics experiment set provides a hands on approach to learning that enhances scientific literacy and critical thinking skills. Specifications: Color: Yellow; Silver Component: ABS, Metal Dynamometer Size: Approximately. 20cm/7.87in Wheeled Car Size: Approximately. 10cm/3.93in Weight: Approximately. 420g Package Includes: 1Set Pulley and Lever Mechanics and Friction Experiment Tool note: 1.Please allow 0-1cm error due to manual measurement. Make sure you donot mind before bid. 2.Due to difference between different monitors, the picture may not reflect the actual color