Swirling water creates a funnel-shaped vortex as it drains from one bottle to another. Educational experimental supplies: good educational and fun experiment and activity for school classes homeschoolers scouts and any other group stimulating kids interest to physics and study Manufacturered by Yunzee. Cultivate your child's manual brain ability and improve your baby's game interest. Let your baby learn and improve in the game Perfect educational materials for preschool elementary kindergarten. Perfect educational toy to teach your children or pupils. Watch your vortex spin in the bottle!!!This is a great educational and fun experiment and activity for school classes homeschoolers scouts and any other group.