ALkaH2o KEI 501 Alkaline Water Ionizer 5 Plate FDA Approved Safe Plastics 7 Presets Limited Lifetime Warranty ELT Certified Safe Self Cleaning 7 Water Options- 4 Alkaline water presets, 2 acidic, and one purified water pH Level Indicator-Range 3.2 to 10.0 pH Oxidation Reduction Potential (ORP) Indicator-Range +600mV to -420mV Self-Cleaning Function and Indicator-Unit cleans itself for 10 seconds by reversing plate polarity after each use and also after every 40 liters. Electronic Testing Labs (ELT) certified safe!