Replacement 4 Filter Kit for Alkaline Reverse Osmosis Water System EDEN RO5-100-ALK 5 micron polyspun Sediment Filter cartridge 2.5-inch x 9.75-inch 10 micron Carbon Block Filter cartridge 2.5-inch x 9.75-inch Alkaline Mineral Filter cartridge 2.5-inch x 9.75-inch Inline GAC Filter 2-inch x 10-inch 1/4-Inch FPNT The alkaline filter is not an inline filter. It is a standard size cartridge.