This is a thermometer with five glass spheres, each with a plate engraved with a temperature. The spheres move up and down depending on the temperature, providing a visual indication of the room temperature. I have it placed by a window, and I enjoy watching the spheres move slowly. ^ ^ It's the largest size, so it has a strong presence and is highly recommended. ^ ^ Approximate Size: Height: 34.5 cm, Base Diameter: 8 cm Measuring Temperature: 20°C to 28°C 20°C is black, 28°C is orange, and the intermediate temperatures are light orange. [Product Description] The physicist Galileo Galilei discovered that the specific gravity of liquids changes with temperature. This thermometer is made using that principle. Glass Float Thermometer Thermometer Aquarium Fish Science Educational Toy Shichida Method Montessori Kodomo Challenge Kumon Gakken Z-Kai Temperature Tabletop Accessories ACTUS Francfranc Afternoon Tea Flying Tiger ITS'DEMO unico LOFT PLAZA Hands IKEA MUJI (Muji) NITORI KEYUCA