Description: 8pcs Bottle Water Science Cyclone Tube Experiment Sensory Watch your spin in the bottle!!!This is a great educational and fun experiment and activity for school classes, homeschoolers, scouts and any other group. Create a from two liter plastic bottles, water and a colorful plastic connecting tube. Swirling water creates a funnel-shaped 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. Quality and durable: made of plastic of good quality, providing long servicing life, and the surface of connectors has stripes, thus much easier for you to rotate. Specification: Material: Plastic Color: Color will be sent randomly Size: approx. 4.8x3.1cm / 1.9x1.2inch Package Includes: 4 Packs Cyclone Tubes(A pack of 2) : Due to the difference between different monitors, the picture may not reflect the actual color of the item. Due to manual measurement, there may be 1-2mm error in size.