pH Buffer Calibration Solution Kit 2-Pack — one pH 4.00 (red) and one pH 7.00 (Yellow), Each 500 mL (1.06 Pint) — NIST Traceable Reference Standards for All pH Meters

Price was right. Works to balance my spa for correct pH range

I would recommend this product

Will be a future customer for sure!! This solution is very Accurate, have compared it to other solutions and there is no comparison if you are looking for accurate solution to calibrate your Ph meter.. FYI..if you are using a Bluelab PH pen made in the last year or 2...Throw it away and do not trust it!! Lots and lots of people complaining about inaccurate readings and the pH Pens going bad and will not calibrate...Then bluelab not standing behind their products or their warranty!!

The pH meter and the test results are useless without checking and calibrating your meter.

Works great for calibrating our ph meter. For our sushi bar. Like it has expiration date. And pappaperwork.

Products made August and October 2018 with expiration dates of August and October 2020! I own and operate a small cheese plant so don't use a lot of product. Nice to know it won't expire before I use it up. Rapid delivery as well.

I have used testing calibration solutions like this for many years and these products are a great value for the money. Plus, they come with certifications traceable to NIST!

I like the products. I use them for calibrating PH meter to check if the instrument is reading correctly

LOVE the downloadable certificates of analysis on the manufacturer website. Makes audit preparation so easy.