Do you want a set of professional pulley block to help you to do experiments This can be your best choice. Very precise and nice. With it, you can easily get the data. Also can be wonderful teaching tool, which is essential to physics and mechanics experiments. Features -Color: As Shown -Material: Plastic -Size: Approx. 33.50X15.70X8.00cm / 13.17X6.17X3.14in - A fun way to introduce kids to fixed pulley, movable pulley, mechanical advantage and the conservation of energy. - Improves kids imagination through interactive play, you can also get involved. - Made of plastic material, durable and practical. - Children create their own structure, exercise their practical ability, train observation capability, thinking and analytical skills. - Perfect for any home, school, or laboratory. Can be used to demonstrate the principle of pulley and how they work in real-world machines. About Shipping: All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances.Any questions, please feel free to contact us During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours, wish you a happy shopping Thanks for your cooperation and well make you feel satisfied.