DIY Assembly Physical Learning Kits: Waterwheel Experiment Come with unassembled parts and instruction: assemble the experiment by yourself Work Theory: Lever principle and gear transmission. Trains childrenand 39 s hands and eyes coordination, fine motor skills, stimulate observation and thinking abilities Great and interesting physical educational toy, also good for parent-child interactive game Material: Plastic Color: As picture show Specification: Assembled Size: Approx. 17.7 x 10.3 x 8.3 cm or 6.97 x 4.06 x 3.27 inch Package Includes: 1 DIY Waterwheel Experiment Kit (Includes Chinese Manual) : Due to the difference between different monitors, the picture may not reflect the actual color of the item. Due to manual measurement,there may be 1-2mm error in size. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.