Pentek EP-20BB Carbon Block Cartridge 4.5" X 20" 5 MicronEP Series Carbon Block Cartridges are manufactured using a process that yields a cartridge with a nominal 5 micron filtration rating and high dirt holding capacity. A high porosity design helps prevent the cartridge from plugging before its absorption 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