Dissolved Oxygen Meter, Dissolved Oxygen Range 20 to 45 mg/L, Waterproof IP54, Automatic Temperature Compensation Yes, Operating Temp. Range (F) 50 Degrees to 104 Degrees , Operating Temp. Range (C) 5 Degrees to 40 Degrees , Display LCD, Auto Power Off Yes, Memory 30 Data Sets, Calibration 1 or 2 point, Power Source (4) AAA Batteries, Manufacturers Warranty Length 1 yr, Number of Tests 0