APEC Water ultimate series FILTER-MAX45-38 is for RO-45, RO-PUMP and compatible with all 10 inch industry standard reverse osmosis water filter system - with 3/8 inch quick dispense upgrade Includes(1) sediment,(2) Carbon block filters,(1) Dow Filmtec membrane and (1) 3/8 inch quick connect inline Carbon filter Filmtec 50 GPD membrane is individually lab tested for the highest rejection rate Certified to remove up to 99% of all contaminants for the best Drinking water quality possible APEC Water's extruded solid carbon block filters far surpass GAC filters in performance and absorptive capacity; in addition they DO NOT leak Carbon fines