The Hanna Checker® makes advanced automation and simple one-button operation available at just $29. No manual adjustment for calibration. Big screen for easy viewing with a stability indicator to alert you when a stable reading has been obtained. Works for over 1,000 hours on one battery. Even better, you can replace the electrode for just $15 giving you a pH meter that can last years. Electrodes on all pH meters fail over time. Having a replaceable electrode means that you don't have to throw out your meter when this happens. Just unscrew the old electrode and screw in the new one. Pricing includes the HI98103 Checker, HI1271 pH electrode with cap, 2 x 4.01 buffer solution sachets, 2 x 7.01 buffer solution sachets, 2 x cleaning solution sachets, and plastic carrying case. The HI98103 Checker pH tester has been designed with many advanced features while maintaining the look and feel of the original Checker. The redesigned Checker now offers automatic calibration to one or two points, automatic buffer recognition, calibrated buffer tags, stability indicator, low battery indicator, and selectable automatic shut off. The Checker still maintains the iconic pentagon design with a probe that measures 103 mm in length and tapered to a 8 mm diameter making it ideal for test tubes and vials.