The Amer Thermal Instruments Liquid Crystal Vertical Aquarium Thermometer is a reliable and accurate way to measure the temperature in your aquarium. With a small and durable design, this thermometer is perfect for use in smaller tanks or in places where you want to avoid contact with chemicals or fish. The liquid crystal display makes it easy to read the temperature, while the 500 millisec response time ensures that the temperature is up quickly. This thermometer is also waterproof and shockproof, making it a great choice for use in any aquarium environment.