1High accuracy, measuring range is 2.0016.00PH, resolution is 0.01PH. 2With a highsensitivity probe, it can respond quickly and support 3point automatic calibration. 3Backlight test paper function, the color of the backlight will change with the PH value. 4Poweroff data storage function, the data is automatically saved for one month after battery is removed. 5Reset function, press and hold power button for 3s in the power-on state, when the screen appears: "----" reset successfully.Item Type: PH TesterMaterial: ABSWeight: Approx. 110g / 3.9ozCalibration Method: 3-Point Automatic CalibrationResolution: 0.01PHBattery: 2 x 1.5V LR44 Button Battery (Battery Not Included)Range: -2.00-16.00PH (Usually 0.00-14.00PH)Reset Function: Press and hold the power button for 3 seconds in the power-on state, and then release it. When the screen appears: "----" Reset is successful.Power-Off Data Storage Function: The data will be automatically saved after the battery is pulled out, and the storage time will be one month.Backlight Test Paper Function: The color of the backlight will change with the PH value.Size: Approx. 155x32mm / 6.1x1.3in1 x PH Tester (Battery Not Included)1 x Manual1.Please allow 0&8209;1 inch error due to manual measurement. Thanks for your understanding.2.Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.