This listing is for 3 filtersThis Pentek C1 carbon filter cartridge reduces fine sediment and chlorine taste and odor in residential drinking water. It has a nominal (85%) filtration rating of 5 microns, and will reduce free available chlorine (FAC) at 2 parts per million (ppm) by at le5ast 75% in up to 2500 gallons at a recommended flow rate of 1 gallon per minute (gpm). This cartridge is made of cellulose media impregnated with powdered activated carbon (PAC), reinforced by polyester backing and netting for strength and dirt-holding capacity. The nitrile butadiene rubber (Buna-N) gasket seals the cartridge against the housing (sold separately). The cartridge has an initial pressure drop of 4 pounds per square inch (psi) at a flow rate of 5 gpm, and it operates over a temperature range of 40 to 125 degrees F (4.4 to 51.7 degrees C). This filter cartridge meets National Sanitation Foundation/American National Standards Institute (NSF/ANSI) standard 42 for quality assurance, and is for use in various applications, including drinking water purification, laboratory water treatment, and film processing, among others .SpecificationsNominal filtration rating5 micronsChlorine reduction capacity2500 gallons at 1 gpmInitial pressure drop at 5 gpm4 psiOperating temperature range40 to 125 degrees F (4.4 to 51.7 degrees C)Maximum dimensions (H x W)9-3/4 x 2-1/2 inches (248 x 64 mm)Materials certificationNSF/ANSI standard 42The nominal filtration rating is for a particle removal efficiency of 85%. 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.