A high porosity design helps the cartridge from plugging before its adsorption capacity is exhausted, maximizing the utilization of the carbon while maintaining low pressure drop. These cartridges are protected by a uniquely formulated polyolefin bilaminate pre-filter, designed to significantly increase the useful life of the cartridge by trapping sediment that typically plugs carbon block cartridges. EP Series Cartridges make an ideal choice for a wide range of residential, food service, commercial and industrial applications. GREATER CHLORINE TASTE & ODOR REDUCTION than competitive 10 Micron carbon blocks FITS ALL 10″ Big Blue housings or other 10″ heavy duty housings and can replace any 10″ x 4.5″ carbon filter cartridge HIGH POROSITY DESIGN helps prevent the cartridge from plugging before its adsorption capacity is exhausted NSF INTERNATIONAL tested and certified for your peace of mind 22,000 GALLON CAPACITY. Replace every 6 months or when you notice a drop in water pressure or water quality.