Pentek® EP 10", 5 Micron Carbon Block CartridgeYou are purchasingeight pieces of the filters.EP Series carbon briquette cartridges are manufactured using a patented process that yields a cartridge with a nominal 5-micron filtration rating, high dirt-holding capacity. A high porosity design helps prevent 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 Endurawrap®, 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 are manufactured entirely from FDA-compliant materials making them an ideal choice for a wide range of residential, food service, commercial and industrial applications. Pentek is the largest brand in the filtration industry Pentek is the originator of carbon block production technology. Pentek is the largest producer of carbon blocks worldwide.