The Milwaukee Waterproof pH51 Tester is one of our most accurate low cost, rugged and reliable pH testers in the market featuring the ability to easily replace the probe providing for years of carefree use. It's simple 2 point manual calibration is simple-to-use. Ideal for use in aquariums, hydroponics, horticulture, pools and many other applications. The Milwaukee pH51 is ideal for applications that require fast, accurate results without complicated set-up. The waterproof pH51 has an accuracy of0.1 pH and is easy to read. With a simple 2-point manual calibration, this pH tester is quickly calibrated to an accuracy usually found in other price ranges.Milwaukee waterproof pH Tester pH51+ fast easy to read results with large digital LCD readout+ extreme pH accuracy to0.1 pH with a pH range (0.0 pH to 14.0 pH)+ resolution: 0.1 pH+ lightweight and portable+ easy measurement: just place the probe in the sample, gently stir, wait for the stability indication to show a stable reading and