Create a tornado from two 2 liter plastic bottles water and a colorful plastic connecting tube. Swirling water creates a funnel-shaped vortex as it drains from one bottle to another. You can create different ways to work with it by timing the water draining using bits of paper or food coloring or lamp oil. Manufacturered by Angel3292. A perfect birthday gift for your kids or friends. Science Experiment Children Assembly Model Toy Baby kids early educational toys Kids Developmental Toy Educational Puzzle Game Toy Kit Music English color words Learning Toy Kids Adult Intelligent Toy children Early Learning toys 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.