pH Buffer Calibration Solution 3-Pack: pH 4.00 Buffer, pH 7.00 Buffer, and Electrode Storage Solution — 250 mL (8.4 fl oz) Each — NIST Traceable Reference Standards for All pH Meters

These standards are the same quality you’d expect from major lab suppliers. They work great for my bench top pH meter.

Great product. Will buy again. Accurate and high volume for the price.

Great stuff. Love the print-out you get that tells the purchaser about the chemicals used and any hazards with them. Very professional. I will use nothing else for any PH pen.

These buffers are a bit more epensive than bargain brands, but you're paying for highly accurate pH calibration, traceable to standards. For a serious analytical or academic lab, using a high-end pH meter, this is value added at an excellent price.For your aquarium or hydroponic garden, and your pocket pH meter, it's not really necessary; go with the generic half-gallon jugs, or better yet, powder packets.

I use this product for calibrating pH pen. It works great. I put a small amount in a medicine cup and then follow directions for pH pen to calibrate. I highly recommend.

Lab grade pH readings.

Good value and works perfect for my meter. I like to test at 4 and 7 to be accurate. Would recommend!

Well-made products. Each one has a date stamp that comes with it verifying its quality signed by the chemist. Well packaged and I just felt like I got something that they cared about when they produced it.