The Pentair Pentek EP-20 is part of the Pentair EP Series of carbon blocks. The EP Series are surrounded by a pre-filter that traps sediments capable of plugging the carbon block cartridge, thus extending the filters service life. The porous design of the carbon block filters also minimizes plugging and promotes low pressure drop of water passing through. Combined these allow for the Pentair Pentek EP-20 to filter up to 5 microns for an extended service life.