APEC Water Systems FILTER-SET-ES High Capacity Replacement Pre-Filter Set For Essence Series Reverse Osmosis Water Filter System Stage 1-3 APEC Water essence standard capacity pre-filter set (FILTER-SET-ES) Includes (1) sediment and (2) carbon block filters to protect and extend the life of the ro system 1st stage polypropylene sediment filter to remove dust, particles, and rust 2nd & 3rd stage extruded Carbon block filters to remove chlorine, taste & odor High performance replacement filters are compatible with all standard sized under counter ro systems