pH Buffer Calibration Kit 3-Pack: 250 mL (8.4 fl oz) Each of pH 4.00, pH 6.86, and pH 9.18 — NIST Traceable Reference Standards for All pH Meters;

These buffer calibration solutions are suitable for the calibration of all pH meters. Each production lot is manufactured in our USA laboratory following carefully controlled written procedures and standardized against NIST standard reference materials (SRM) for highest accuracy. The finished product is assigned a unique Lot number and expiration date. These products will have greater than one year shelf life when received.