pH meter calibration solution kit, includes pH 4.00, 7.00, and pH electrode storage solution, pH calibration buffer solution 250 ml*2, pH probe storage solution 30 ml*1, pH tester accessories.

["High precision pH buffer calibration solution set: Provides values with an accuracy of +/- 0.01 pH at 25 °C. You can use the GIDIGI pH meter for an extended period of time and receive an accurate pH buffer calibration solution.", "Special pH electrode protection solution: Regular replacement with a new pH electrode protection solution can help keep the probe in optimal condition and extend the life of the tester.", "pH solution with stable ingredients: Does not evaporate easily after opening, ensuring accurate measurement values. Unopened bottles are shelf-stable for 3 years from the manufacturing date.", "Color-coded for easy identification: pH 4 is pink, pH 7 is green, and the pH electrode protection solution is transparent. We recommend calibrating your pH meter regularly to ensure it is more accurate and helps you check the quality of hydroponic nutrient solutions, household water, and drinking water.", "Large capacity: Each bottle of pH solution contains 250 ml, suitable for long-term use with all pH meters, and ideal for pharmaceutical, academic, research, and industrial laboratories."]