With high-performance microcomputer chip and high-accuracy sensor,the thermometer can check the temperature inside aquarium tanks more accurate.As its build-in probe of completely waterproof designs.Design with compact,decent,novel and faddish appearance.Using LED digital display,temperature can be shoen clearer and be checked easier even in long distance,wider angle of view,or night time.Type of sensor: Build in temperature-sensitive resistance sensor Sticking inside aquarium tank with its suctions.HAKAWIN Digital display waterproof Thermometer for both Fresh and Marine Aquarium.