VIVOSUN Digital pH and TDS Meter Kits, 0.01pH High Accuracy Pen Type pH Meter 2% Readout Accuracy 3-in-1 TDS EC Temperature Meter for Hydroponics, Pool and Aquarium, Yellow Blue, Application: Great for all home and laboratory TDS & pH testing applications including aquariums, swimming pools PH Meter: Full measurement range of pH 0 - 14, reliable and quick readings 3-in-1 TDS Meter: Measurement Range 0-9990ppm, 0-9990µs/cm; Accuracy ± 2%, 0.1- 80.0°C, 32.0-176.0°F; Note: This meter can't test sea water Features: Comes with protective case; Lightweight, handheld design for portability and convenience Included: PH meter, 3-in-1 TDS meter, 3 calibration buffers