Pentair Pentek EP Series Carbon Block Cartridges are manufactured using a process that yields a cartridge with a nominal 5- filtration rating and high dirt-holding capacity. 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.