Kids learn about the forces of nature and how air pressure and density work together as they create their very own tornado in a bottle! Just fill one of two plastic soda bottles (not included) halfway with water…use this tube to connect the bottles…tip the bottles so that the one with water is on top…and move the bottles in a circular motion. In seconds, a whirling tornado appears! You can even create special effects by adding food coloring or glitter (not included) to the water. Plastic tornado tube measures 1 3/5" and comes in assorted colors.