The Sure Test? Commercial Multi-Meter allows for easy measurement of pH and conductivity (EC or TDS) and temperature (?F or ?C) in one versatile unit. It also has the ability to measure dissolved oxygen (DO) with the optional DO probe (#716388, sold separately) making it the most versatile handheld multi-meter available. This rugged meter includes automatic temperature compensation (ATC) for more precise pH readings. Easy-to-use and calibrate, this meter is an excellent choice for all-in-one nutrient management anywhere you take it. Comes with replaceable conductivity probe (#716382), replaceable pH probe (#716386), hard carrying/storage case and 6x AAA batteries. Waterproof housing (IP65 rated).