2 Point Manual Calibration, Accuracy of ±0.2 pH. Set Point Range: 5.5 to 9.5 pH, LED Visual Alarm Active & Power Plug Socket for Dosing turned on when reading is Higher or Lower ( user select ) than the set point. Supplied with 12 V DC Power Adapter, MA911B/2 Double Junction pH Probe, 20 ml. pH 7.01 Calibration Solution and Screwdriver for Calibration. Unit comes with Mounting Kit and Probe Holder