1. Traditional and Reliable: Made of high - quality glass, this thermometer uses a traditional thermometric glass rod design. It has been a trusted choice for measuring fish tank temperatures for a long time. The glass material is durable and resistant to corrosion in the aquatic environment. 2. Simple to Read: The markings on the glass thermometer are clear and easy to interpret. You can directly read the water temperature by looking at the position of the liquid column in the glass rod. It provides a straightforward way to monitor the temperature without the need for complex electronic components. 3. Direct Water Contact Measurement: By being placed directly in the water, it can accurately measure the water temperature. It is a basic yet effective tool for fish tank owners who prefer a simple and reliable method to keep track of the temperature in their aquariums.