MERRITO 20pcs Merrito Pack pH Buffer Solution Powder for Precise Calibration of pH Meter, pH Calibration Powder Solution 6.86,4.01 pH Indicators

High Accuracy. Compatibility: Suitable with most of pH meters, Ideal for Calibrating. Good Quality: Produced with premium material. Sealed by durable moisture-proof individual packet. Easy to use: Mix the buffer powder with 250ML distilled water, put the pH meter in the solution and gently stir and wait a few seconds for the result. 20 Packets: 10* pH 4.01 Solution powder, 10*pH 6.86 Solution powder, cost-effective and flexible for using.