Cep-20e thin wall coconut carbon block, this Pentek cep-20e coconut carbon block filter cartridge reduces fine sediment and chlorine taste and odor in residential and commercial drinking water. It has a nominal (85%) filtration rating of 5 microns. It will reduce free available chlorine (fac) at 2 parts per million (ppm) by at least 75% in up to 20,000 gallons at a flow rate of 2 gallon per minute (gpm). the cartridge is made of acid-washed coconut shell based carbon block media enclosed in a polyolefin wrap pre-filter and polyethylene outer netting. The filter has an initial pressure drop of 3 pounds per square inch (psi) at a recommended flow rate of 2 gpm, and operates over a temperature range of 40 to 125 degrees f (4.4 to 51.7 degrees c). this carbon block filter cartridge meets national sanitation foundation/American national standards institute (nsf/ansi) standard 42 for quality assurance, and is for purification of residential and commercial drinking water.