This Pentek GAC-20BB carbon filter cartridge reduces chlorine taste and odor in residential and commercial drinking water. It will reduce free available chlorine (FAC) at 2 parts per million (ppm) by at least 75% in up to 25,000 gallons at a flow rate of 4 gallons per minute (gpm). This cartridge is made granular activated carbon (GAC) filter media encased in polystyrene with a spun polypropylene post filter. The nitrile butadiene rubber (Buna-N) and Santoprene (TPE, thermoplastic elastomer) gaskets seal the cartridge against the housing (sold separately). The cartridge has an initial pressure drop of 5.0 pounds per square inch (psi) at a flow rate of 4 gallons per minute (gpm), and operates over a temperature range of 40 to 125 degrees F (4.4 to 51.7 degrees C). This carbon filter cartridge meets National Sanitation Foundation/American National Standards Institute (NSF/ANSI) standard 42 for quality assurance, and is used for treatment of residential and commercial drinking water.SpecificationsPost filter20 micronsInitial pressure drop at 4 gpm5.0 psiChlorine reduction capacity25,000 gallons at 4 gpmTemperature range40 to 125 degrees F (4.4 to 51.7 degrees C)Maximum dimensions (H x W)20 x 4-1/2 inches (508 x 114 mm)Materials certificationNSF/ANSI standard 42 Chlorine reduction capacity is the minimum total amount of water for which the free available chlorine (FAC) at a concentration of 2 ppm is reduced by at least 75%.H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.Water filters remove undesirable particles, chemicals, and microorganisms from water by means of a semipermeable barrier, adsorption, or biological processes. They are made of densely packed synthetic or natural fibers that trap suspended particles, materials that block microbes or adsorb unwanted chemicals, or substances that cause a chemical change, such as acid neutralization. For most residential, commercial, and industrial applications, water filters are manufactured in the form of replaceable cartridges that fit inside permanent housings. Filtration systems typically consist of a series of two or more types of filters, each designed to remove different contaminants. The performance of filters is measured by the minimum particle size that is blocked, the percentage of particles or microorganisms that are removed, the downstream concentration of unwanted chemicals, the maximum flow rate, and the amount of water that can be filtered before the filter must be replaced. Water filters are used in a wide range of applications, including drinking water purification, swimming pools, industrial processes, and irrigation, among others.Pentair manufactures industrial, commercial, and residential water filtration components and systems. The company, founded in 1966 and headquartered in Minneapolis, MN, meets International Organization for Standardization (ISO) standards 9001 and 14001 for quality assurance.