With it’s easy to read illuminated display, one-touch calibration system, super clear instructions and no buttons to push, measuring pH just got a whole lot simpler. The flashing lights you love so much; the easiest calibration system ever; reliability only Bluelab products can provide; longest lasting probe on the market AND it’s replaceable; auto on just like the Bluelab Truncheon; Automatic Temperature Compensation; a scale of 2.0pH - 10.9 pH.