Features: Package includes: 2Pcs Double Pulley, 2Pcs Single Pulley, 1Piece Fixed Pulley, Levers, Dynamometer, 6Pcs 20g Hook Weight, Pulley Bracket, 2Pcs Installing Nails, Cotton Strings, Base. Unlock the mysteries of mechanics and friction experiment with our Pulley and Lever Mechanics Friction Experiment Set, must have physics teaching aids 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 fixed pulley, movable pulley, mechanical principles 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 Component: ABS, Metal Base Size: Approximately. 17cm/6.69in Double Pulley Size: Approximately. 11cm/4.33in Single Pulley Size: Approximately. 8cm/3.15in Pulley Bracket Size: Approximately. 14cm/5.51in Levers Size: Approximately. 34.50cm/13.58in Dynamometer Size: Approximately. 20cm/7.87in Weight: Approximately. 400g Package Includes: 1Set Mechanics Experiment Supply 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