This is a "high quality - low cost" cartridge set for the Water Factory SQC-3 reverse osmosis system. This water filter cartridge set includes (1) KWPSQC-2 sediment / carbon pre-filter which is a compatible replacement to Water Factory filter cartridge 47-55706G2. Also included is (1) KWPSQC-4 carbon block filter which is a compatible replacement to Water Factory filter cartridge 47-55710G2. This set should be changed annually to adequately protect the reverse osmosis module and keep the system in peak performance. The module (membrane) should be changed when the total dissolved solids number becomes elevated or permeate water production is diminished. One of these circumstances is typically realized between 3-5 years. If you require the cartridge set with the module included please insert our model KWPSQC-Module-2&4 in the Amazon search bar.