If you are looking for PH meter buffer solution powder for precise and calibration, then your research is over here. Our product can meet your need. Adopted of seal packing, it is practical and for long time use. Individually wrapped to maintain freshness until use. Features -Color:Assorted Color -Material:ABS -Size:7.00X6.00X0.50cm/2.75X2.36X0.20in -You will obtain the calibration solution powder of 4.01, 6.86 and 9.18, and abundant enough to satisfy your daily pH needs. -Small in size and light in weight, Individual sized packet, can carry it out anywhere, store it anywhere you need. -As this is a powder, in a sealed packet there is no "shelf life". Just add distilled water to mix and use. -Easy to use, no need to measure, you just mix each pack calibration solution powder with 250mL distilled water. -The PH calibration solution powder is suitable for testing of drinking water, pool, aquarium, or hydroponics. Package list: 5 x ph4.01 buffer powders 5 x .86 buffer powders 5 x .18 buffer powders