Apera Instruments AI1112 pH Calibration Buffer Solution Kit includes three 8oz bottles of pH buffer solutions (pH 4. 00, pH 7. 00, and pH 10. 01), three 8oz bottles of conductivity (EC) standard calibration solutions (1413 µS/cm, 12. 88 mS/cm, 84 µS/cm), one 4oz bottle of 3M KCL storage solution for pH/ORP electrodes, plus one piece of Apera CalPod Solution Holder, which helps users organize all the solutions in one place and streamline the entire calibration process. All the buffer solutions are standardized against NIST certified references at 25˚C (77˚F). It’s ideal for the calibration of all kinds of pH/conductivity meters. Since pH and conductivity value are affected by temperature, the temperature & pH/conductivity reference charts are provided on the bottle labels for reference. The 3M KCL Storage Solution helps keep the sensitivity and accuracy of your pH probes. All the solutions are double-sealed, not subject to the DOT shipping restrictions, and have a 2-year shelf life (1-year for conductivity solutions). Keeping the standard solutions fresh and uncontaminated is the precondition for accurate pH measurement. Pour 2-3 oz. of solution into a clean container for calibration. If sealed well, the same amount of pH solution poured out can be used for 10-15 times before replacement (conductivity solution up to 5 times). Never pour the used solution back to the original bottle to avoid contamination. The expiration date is printed on the bottle. MSDS documents are downloadable. COA can be achieved per request. Note: Store at room temperature and away from direct sunlight. Keep the bottle tightly closed when not in use. Keep out of reach of children.