YSI 3824 [603824] pH Calibration Buffer Pack, 2 Pints ea. of pH 4, 7, & 10. Choose between pH, 4, 7, and 10 buffer solutions. Each buffer case contains 6 individual pints (plastic). Buffer cases are available with a single buffer type or with an assortment of buffers (2 pints of pH 4, 7, and 10 buffers).