Our company has established itself supplier of superior quality D.O.Meter. These are used to determine water quality in a variety of applications including wastewater, aquariums, and fish hatcheries. It simultaneously displays DO and temperature readings. Unit holds and recalls minimum and maximum readings. This one features automatic temperature compensation and calibration to air. Meter is ready for use and includes a soft carrying case with belt loop, two spare probe heads, electrolyte and 4 AAA batteries.