Demonstration Pulley Experiment SetThis physics lab equipment contains single pulleys, support rods pulleys, 1 complete total set double pulleys for mechanics experiments MaterialThe pulley block set is made of pp and metal materials that ensures its longevity and maintains its functionality SizesThe pulley diameter mesures 4cm and 3cm Educational Tool Essential physics experimental equipment for students and teachers, great for teaching mechanics effects in physics. Can be used to demonstrate the principle of pulleys and how they work in real machines Wide ApplicationGreat for home, school or lab use. Also ideal Birthday and Christmas gift for kids, children in elementary and middle school, can enjoy DIY experiments fun while learning basic physical science knowledge Specification: Material: PP, Metal Size Chart: Pulleys: Diameters: 4cm/1.57inch, 3cm/1.18inch Package Includes: 1 Pulley Block Physics Experiments Kits