DESIGNED TO FLOAT IN AQUARIUMS: Our Floating Aquarium Thermometers are mercury free, and are designed for a quick, easy, and reliable temperature readings. They’re safe to use inside both freshwater and saltwater fish tanks.
OPTIONAL SUCTION CUP: Each Floating Aquarium Thermometer comes with an optional suction cup, which allows you to place it alongside the tank’s walls for even easier access for a temperature reading. The suction cup mount is removable, and the thermometer should float on its own.