PINPOINT High-Precision pH Calibration Fluids Kit contains 12 packets: 3 pouches of 4.000 +/- 0.002, 6 pouches of 7.000 +/- 0.002, 3 pouches of 10.000 +/- 0.005 Calibration Fluids. Each one comes in it's own plastic envelope packet. They are ready to use, no mixing required, are extremely accurate and field portable. Each packet contains ample fluid for calibration (approx. 25 mL).