Based on the designs of Jacob Leupold and those studied by Leonardo da Vinci, this ornament design replicates the motion of a "perpetual motion" machine called an overbalanced wheel to produce a whimsical wintery decoration for any Christmas tree or setting. The snowflakes are affixed to rollers that spin within the gaps of the larger star, and the imbalance generates additional momentum to drive the overall spinning motion. It won't go forever, but it does go for a while!
For more on perpetual motion, see: https://en.wikipedia.org/wiki/Perpetual_motion