This set combo of pH, TDS meter which could help you to test both of the pH value and water quality in only 5 seconds. Measuring range of pH meter is 0.00-14.00pH, accuracy: +/-0.01pH and TDS testing range is 0-9999ppm, accuracy: ±2% F.S. With automatic calibration function, three points automatic calibration(only 6.86 point calibration: the accuracy is 0.1ph). No need any adjustment before use, convenient and professional. Desinged with LCD backlight which makes the data display clearer than other non-light meter, even in dark situation. Suitable for testing pH balance value and water quality of drinking water, aquariums, pool, spa and other water system, help you to protect the water safety of your daily life.