AQ Series Model AQ 500 Alkaline pH Water Ionizer Adjustable pH monitor... Built-in constant ORP meter readout... pH selection of 4 levels Alkaline pH Range to 4.5 - 10+ .. 5 Platimum Electrodes.. 912 cm2 ... Color LCD - ORP & pH readout ORP --100 to -700 mV (Alkaline Water), 600 mV to 850+ mV (Acid water) ... Flow Rate 1 - 1.5 gal/min Switched-mode power supply (SMPS), AC110V, 150 Watts, CE certification Manufacturers 5 Year Warranty ... Central USA Service Location ... Mfgr - Yi Shan Electric