About this project[Building Building Kit] Planet building with sun earth moon is designed for boy or girl over 6 years old and astronomers. This building set is a science educational toy set to inspire or improve their space astronomy and the perfect planetary decoration for the home.[3-D Solar System] The Earth, Moon and Sun orbit models can be rotated by rotating the rod, the Earth orbits the Sun and the Moon orbits the Earth, showing the orbits of the planets. NOTE: Do not push the gears too tightly.[Safety Building Block Quality] The building blocks are made of high quality ABS, no odor, CPC (Children's Product Certificate) approved, the building blocks have a smooth surface. Bricks compatible with LEGO or other major building brands.[Clear building instructions] The instructions are very clear and easy to understand, guide you brick by brick, and you can easily build bricks. When assembling the various gears, it's important to make sure everything spins freely and doesn't push too hard.