APEC Water Ultimate series FILTER-MAX45 is for RO-45, RO-PUMP and compatible with all 10 inch standard industry reverse osmosis water filter system Includes (1) sediment,(2) Carbon block filters,(1) DOW Filmtec membrane and (1) inline Carbon filter Filmtec 50 GPD membrane is individually lab tested to ensure the highest rejection rate Certified to remove up to 99% of all contaminants for the best Drinking water quality possible APEC's extruded solid Carbon block filters far surpass GAC filters in performance and absorptive capacity; in addition they DO not leak Carbon fines