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.