Measures dissolved oxygen to determine water quality in environmental testing, labs, industrial and municipal waste water, aquariums and fish hatcheries. Designed for simple one-hand operation with automatic temperature compensation and calibration to air. The polarographic probe has a built in temperature sensor and easy to replace pop-off probe heads. Simultaneously displays dissolved oxygen and temperature readings. Also holds readings and recalls minimum and maximum. IP-67 water proof. Comes ready to use in a soft carrying case with belt loop, two spare probe heads, electrolyte and 4 AAA batteries. Dim: 8 x 2 x 1 1/2 inch (180 x 40 x 40 mm). Weight: 6 oz (175 g).