Description Even though, portable PH meters are easy to use, they require calibration at time to time. And this mega value 3-pack calibration kit is time and money saving. These buffer solution powders come in pre-measured packets: Just mix each packet with 250 mL of distilled water, and your calibration solution is ready. Before purchasing, make sure that your meter uses listed solutions for calibration. Feature - Color: As Shown.- Material: Powder.- Size: 5 x 5 x 0.5 cm.-?Included one package of 4.01, one of 6.86 and one of 9.18 calibration solution for all pH needs- Fast and easy. No need to measure, just mix individual packs with distilled water.- Accuracy. Calibration powders enable you to test the pH of your pool, aquarium, water, and more quickly with your pH tester / meter.- Long Term Use. Save time and money by mixing powders in a jar of distilled water. This lets you keep them longer and more readily available without needing more packets.Packing list: 1 x PH Calibration Solvent Powder(PH 4.01)1 x PH Calibration Solvent Powder(PH 6.86)1 x PH Calibration Solvent Powder(PH 9.18)