Feature:1. It's a ring-shaped and twisted glass toy with a liquid in it that boils when heat is transferred from your bare hands.2. It proves the vapour-liquid equilibrium, the colored liquid in the container is a volatile mixture with a boiling point just above room temperature.3. Boil this liquid at your body temperature, hold the lower container with your hand, and observe how the liquid boils and rises through the tube to the upper container.4. Once leave your hand, it takes a few minutes for the liquid to cool and return to the container below, which is a very interesting science toy and a great demonstration of energy transfer.5. The heat on your hand causes the liquid to boil, causing the liquid to evaporate into a gas. The expanding gas pushes the liquid upward, and when you release your hand, the equilibrium is re-established. The gas condenses again into a liquid and flows back to the container below.Specification:Condition: 100% Brand NewItem Type: Thermometer ToyMaterial: High Borosilicate GlassProduct Size: Approx. 16 x 5 cm / 6.3 x 2 inWeight: Approx. 63g / 2.2oz.Package List:1 x Thermometer ToyNote:1. Please allow 0-2 cm error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.