Specification: Material: wood + plastic Size: 25*10*10cm / 9.8*3.9*3.9in Age: over 4 years old Ability development: let the child understand the simple mechanics knowledge through this experiment. Packages: 1 X Crane Assemble Model
Introduction to hand crane: Pulley is a simple mechanical device used to lift heavy objects and save effort. Pulleys are divided into fixed pulley and moving pulley. The central shaft of the fixed pulley is fixed, and the central shaft of the moving pulley can be moved. Using fixed pulley does not save effort or distance, but it can change the direction of applying force. Using a movable pulley can save half the force, but it costs half the distance and cannot change the direction of applying the force. The fixed pulley and the movable pulley are combined to form pulley set, which not only saves effort but also changes the direction of applying force.
Pay Attention: When assembling, pay attention to the red wire connected to the positive pole of the battery box and the blue wire connected to the negative pole of the battery box. All products do not include batteries; accessories color is random. Do not specify the color. Please read carefully before buying. Contains small accessories and sharp objects. Children should be accompanied by adults. Please take care of children and avoid from swallowing. Note: Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you!