Pocket Size pH Meter.  Measures pH 0 to 14 with a .1 pH resolution.  LCD display.  Includes meter, carrying case, calibration screwdriver, 2 x pH buffer powder and manual.

You can use a pH meter to check the pH of your water, mash, [test Star San effectiveness] and finished beer.

pH Tester, Jellas Pocket Size pH Meter Water Quality Tester for Household Water, Pools, Aquariums, Hydroponics, Home brew, pH Measurement for pH 0-14.0, ± 0.1 Accuracy, 0.1 Resolution (Rose Red)