15 Pack PH Calibration Buffer Solution Powder Set, for Precise pH Meter Calibration, Make 250 ml of Each 4.00pH, 6.86pH, and 9.18pH to calibrate Your PH Tester

Works as advertised. Will buy again.

These are a must have to make accurate readings. Being able to buy in bulk is a plus since calibration is recommended frequently. They come in a small box which is great to keep them all in one place. Super easy to use.

Works well.

I make hot sauce and store them in bottles. I use these Calibration Buffer Solution Powder Set to measure its acidity level to keep my hot sauce fresh. I have used them many times and these powder sets haven't failed me yet. I like that it is clearly color-labeled for easy reading.

It's an easy to make buffer solution for pH meter calibration. Since it's a pre measure powder in a sealed packet you can make fresh buffer when needed.

Takes a while to break up and dissolve the product.. I suggest breaking it into a powder in the package since it's "caky" when furst opened.. but otherwise it is extremely accurate and gets my cheapo PH meter to perform like an expensive model..

Product worked as stated, I needed to re- calibrate my ph pens and they worked perfectly three stars are for the condition the box was in when I received it, it looked as if was old and used....

For as often I need to calibrate my pH testers this quantity of buffers is ideal.