Zacro Digital pH Meter with Pack of 6 Free Extra Buffer Powder, pH Pen Tests Water, Aquarium, Pool, Hydroponics, Auto Calibration Button, with ATC, 0.00-14.00 pH Measurement Range The pH meter full measurement range of pH 0.01-14 with 6 packs pH Buffer Solution Powder Easy to carry and convenient to use with handheld pen-type portable design pH meter with ATC function (0~80 ),Auto Calibration The PH tester is great for home and laboratory pH testing applications including household drinking water, aquariums, swimming pools, tap water, RO System, Hydroponics, SPA, and so on