Oakton Acorn pH 6 Portable pH Meter, with pH Electrode, Temperature Probe and Case Kit Push-button calibration capabilities up to three points for a wide range of results Auto-buffer recognition of USA, National Institute of Standards and Technology (NIST) and pure water buffer values for quick calibration Automatic Temperature Compensation (ATC) for accurate readings in fluctuating temperatures Comes with pH electrode and temperature probe for ease of application Large, digital LCD display of pH and temperature for ease of viewing