ExStik 4-in-1 Water Quality Meter measures Chlorine, pH, ORP plus Temperature with interchangeable flat surface electrodes (included). Flat surface electrodes work in liquids, semi-solids and solids. Memory stores and recalls 15 readings and saves last calibrated value. Large 3-1/2 digit (2000 count) Digital display with bargraph (pH bargraph originates at neutral point 7.00pH). Automatic electronic self calibration for Chlorine and ORP; 1, 2 or 3 point buffer calibration for pH. Data Hold, Auto shut-off and low battery indication. Waterproof design floats in wet environment (IP67). Direct reading of Total Chlorine from low detection limit; Unaffected by sample color or turbidity. Simultaneous display of ppm or pH and C/F Temperature. Smart chip predicts pH electrode performance with RENEW indicator when replacement is needed. CAL indicator alerts user to recalibrate pH electrode. Automatic Temperature Compensation. EX900 Kit Complete with ExStik Chlorine meter, gel filled pH electrode, ORP electrode, protective sensor cap, 5 packs of 10 reagent tablets (50 tests), 5 plastic sample cups, weighted stand, pH 4, 7 and 10buffer packs, four LR44 button batteries, carrying case, and neck strap. EX800 Kit is same as EX900 but excludes ORP electrode.