Oakton Waterproof Eco Tester 1 is an economical pH pocket-sized meter convenient for everyday use. Completely sealed and durable, this unit is waterproof and dustproof with a transparent electrode cover/sample cup. Highly effective push-button calibration with auto buffer recognition makes this product as accurate as it is easy to to use. A great addition to your horticultural meters! Range from 0.0 to 14.0 pH. Four batteries included.