The UVMAX D4 Plus Model is a 12 GPM point-of-entry system that renders chlorine-resistant parasites, bacteria and viruses such as Cryptosporidium, Giardia and E. Coli harmless. This system features a UV output sensor, lamp age indicator, malfunction monitor and stainless steel chamber. The UVMAX D4 Plus has been discontinued with the VIQUA D4 Plus as its replacement.