High precision resolution: Thanks to the built-in first-class chip, sensitive electrode and low resistance glass film, the response speed of the TDS pH meter is greatly improved, reaching a real value of 0.01 One-button lock function: When the measurement is stable, simply press the HOLD or TEMP button to lock and display the readings, which is really easy. (Before pressing the "HOLD or TEMP" button, the pH will vary slightly, which is normal.) Versatile: Whether you want to test and control the water quality in the swimming pool, hot tub, your own well or aquarium or from the pipes: the water tester for pH, TDS and EC value will help you in everyday life . Also works as a reliable digital thermometer. Clear digital display with warnings: Show data clearly. Don't worry that the displayed value will be displayed under insufficient light. The water pH tester has a green backlit LCD display so you can clearly see the reading in any situation. When the pH is lower than 3.5 or higher than 12.5, the white digital display will turn red and flash to warn you. Automatic Temperature Compensation: Temperature may affect the readings, our water meter's automatic temperature compensation can ensure you get the best reading possible. Temperature compensation function, which allows you to measure water quality more precisely. Delivered quantity: 1 piece Welcometomeet