?COMPATIBILITY. Ideal for the pH calibration of all pH meter/tester.
?TOTAL 15 PACKS. It can make 15 x 250ml pH buffer solution. The package Including 4.01, 6.86, 9.18 pH buffer powder each 5 bags.
?ACCURATE. Produced with premium quality material under strict conditions, and pre-measured exactly to ensure accuracy.
?EASY TO USE. No need measure, just mix individual pack with 250ml distilled water separately, you'll get standard PH solution kit.
?LONG TERM USE. sealed by durable moisture-proof individual packets, 3 years shelf life.