USWF-PP20-2045 is a 20 micron 20"x4.5" pleated polyester sediment replacement filter that is proudly manufactured in the USA. It is made from FDA Title 21 compliant polyester fabric pleated around a polypropylene core to provide a high quality filter independently tested to NSF / ANSI standards 42, 61, and 372. Pleated filters offer the lowest pressure drop and highest flow rate of all sediment filter types by providing as much filtration surface as possible to maximize water flow. However because pleated filters offer no filtration gradient or depth they are best suited to filter sediment of uniform particle size. USWF only carries pleated polyester filters. The synthetic filter media can be used on both treated and untreated water supplies. The pleated polyester is also highly durable meaning that you may rinse and clean the filter once it becomes clogs to extend the filter life. This American made filter is a compatible replacement for other popular pleated sediment filters like the Pentek S1-20BB, Hydronix SPC-45-2020, and more.