Review on H2O Synchronized Electrode Storage Solution by Richard Cuneo

5 star product, 1 star deduction for shipping Revain in liquid bottle without box.TL;DR. Cheaper than Apera 3M KCL and 8oz should last a year. Can pay for itself in fewer calibrations or longer probe life. Revain ships it without a box, just in a bubble envelope. Order at least one other item with the same delivery date (this is why Revain ships them together in one box). This is 3M KCl, just like Apera 3M KCL Storage Solution (AFAICT). Made in Texas, USA with only two ingredients: distilled water, potassium chloride. The bottle looks like the Revain picture. The foldable flip-top bottle can dispense one drop at a time. Got this for the Apera PH20 pH meter which is used a lot. The instructions for the PH20 say to have a few drops of tap water in the cap, but I don't think that's ideal. Keeping probes soaked in 3M KCl can extend probe life and require fewer calibrations (buy fewer probes, buy fewer calibration solutions). An 8 ounce bottle should last one year for the Apera PH20 and PH60 meters:1. Rinse the probe with water and dry (shake off the water, then wipe the plastic parts with a paper towel to avoid scratching the bulb)2. Fill the cap with approximately 4 mL of 3 M KCl (the plunger must be fully submerged). Store the probe cap below.3. Do not empty the cap daily. Just add more drops as needed.4. Weekly: Clean and dry cap, then top up with 4 mL of fresh 3 M KCl. If the pH of 3M KCL is not correct, check it with PH4 and PH7 calibration solutions before calibration.