The Milwaukee pH55 PRO is a waterproof pH/temperature tester with two-level LCD display for temperature and pH. An easily replaceable probe and extended pH range make it perfect for almost any application. Simple automatic 1- or 2-point calibration is easy to use and offers two sets of stored buffers to choose from. The Milwaukee pH55 PRO is ideal for use in aquariums, hydroponics, horticulture, schools, swimming pools and many other applications.Milwaukee waterproof pH Tester pH55 PRO+ fast easy to read results with large digital LCD readout+ extreme pH accuracy to0.1 pH with an extended pH range (-2.0 pH to 16.0 pH)+ temperature accuracy: +/- 0.5C+ resolution to 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 then freeze the reading+ is fully compensated for temperature (ATC) from -5 to 60C+ simple Automatic one or two-point calibration+ 2 Sets of pre-memorized buff