The blue of the sea.
A gyroscope refers to a rigid body that rotates at high speed around a fulcrum. It is one of the earliest entertainment tools among Chinese folk and first appeared in historical records of the Late Wei Dynasty.
The upper part of the top is round and the lower part is sharp. When playing, you can wrap it with a rope and pull the rope hard to make it rotate upright, or use the elasticity of the spring to rotate. When it rotates, it not only rotates around its own axis, but also makes conical motion around a vertical axis. Because its color is blue, it is named Sea Blue.