【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 【EASY CALIBRATION】: This PH pen is featured with auto temperature compensation which can be adjusted to water temperatures and water quality to give PH readings almost instantly. As well, the tester can be tested with using Buffer Powder.