This Pentek R50-BB pleated polyester filter cartridge reduces sand, dirt, silt, rust, and scale particles in residential and commercial water. It has a nominal filtration rating of 50 microns at an efficiency of 85%. The filter is made of resin-impregnated cellulose and polyester media pleated around a polypropylene core for strength. It has an initial pressure drop of less than 1 pound per square inch (psi) at a flow rate of 10 gallons per minute (gpm), and operates over a temperature range of 40 to 125 degrees F (4.4 to 51.7 degrees C). This pleated polyester 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, irrigation, and industrial processes, among others.SpecificationsNominal filtration rating50 micronsInitial pressure drop at 10 gpmTemperature range40 to 125 degrees F (4.4 to 51.7 degrees C)Maximum dimensions (H x W)9-3/4 x 4-1/2 inches (248 x 114 mm)Materials certificationNSF/ANSI standard 42 The nominal filtration rating is for a particle removal efficiency of 85%.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.