Continuous Hydrometer with Digital Thermometer

The unique, patented design of this hydrometer enables it to be installed inside the aquarium or used external to the tank. Simply hang it inside the aquarium to provide a continuous "real time" reading of specific gravity. In addition, it can be used as a typical hydrometer for periodic measurements. Includes a digital thermometer to insure tested water is at correct temperature. Approximately 5 x 3-1/2 x 3/4.