This listing is for 8 pieces filters. Reduces sand, silt, scale, and rust particles in residential and municipal drinking water and industrial fluid applications Nominal filtration rating of 50 microns Fibrillated polypropylene cord wound on a polypropylene core for strength and minimum extractables Initial pressure drop of 8 psi at a flow rate of 30 gpm Temperature range of 40 to 165 degrees F (4.4 to 74 degrees C). This Pentek WPX50BB97P string-wound polypropylene filter cartridge reduces sand, silt, scale, and rust particles for municipal drinking water and industrial fluid applications. It has a nominal filtration rating of 50 microns at an efficiency of 85%. The filter is made of fibrillated polypropylene fiber cord to minimize extractable compounds from the media, and the cord is wound on a rigid polypropylene core for strength. It has an initial pressure drop of 8 pounds per square inch (psi) at a maximum flow rate of 30 gallons per minute (gpm), and operates over a temperature range of 40 to 165 degrees F (4.4 to 74 degrees C). This string-wound polypropylene filter cartridge is for use in various applications, including drinking water purification, irrigation, and industrial processes, among others. Specifications Nominal filtration rating 50 microns Initial pressure drop at 30 gpm 8 psi Temperature range 40 to 165 degrees F (4.4 to 74 degrees C) Maximum dimensions (H x W) 10 x 4-1/2 inches (254 x 114 mm) 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.