Simply the most reliable pocket pH tester with the best value for general-purpose pH testing e.g. hydroponics, horticulture, pools and spas, water treatment, beverage making, education, environmental monitoring, etc. Up to 3 points of Auto. calibration and 0 to 50˚C Auto temperature compensation (ATC), 0. 1 pH Accuracy with 0 to 14. 0 pH measuring range; Auto. recognition and indication of stable values improves repeatability, saving you the trouble of guessing when to manually hold measurement. PH20 comes with a complete kit of premixed calibration solutions (4.00 and 7.00), 4 AAA batteries, and a lanyard all in a portable carrying case. Smart Self-diagnosis, warning of incorrect buffer solutions and incorrect calibrations. IP67 water-resistant. Up to 2000 hours' operation powered by AAA alkaline batteries. The product is CE and RoHS certified, and is manufactured under an ISO 9001: 2015 certified quality system.