APEX RF-3020 Whole House Water Filtration System Replacement Filter Cartridge Pack 20" Polypropylene sediment pre-filter extracts suspended materials such as sediment, rust, insects, and other particles down to 5 micron. Multi-stage 20" filter that consists of 1 micron filter pad, Activated Alumina, another 1-micron pad & Granular Activated Carbon (GAC) effectively removes fluoride, arsenic, chlorine, heavy metals and hundreds of contaminants from water. NSF approved, acid washed, high performance coconut shell activated carbon filter absorbs heavy chlorine byproducts such as chloramines, THM, and TCE. Genuine APEX replacement filter kit for MR-3020 Whole House Filter.