Pentair Pentek WP25BB20P Big Blue Sediment Water Filter, 20-Inch, Whole House Polypropylene String-Wound Filter Cartridge, 20" x 4.5", 25 Micron, keeps your water clean and protects your appliances by removing dirt, sand, silt, and particulates. It fits all 20" Big Blue Housing and can replace any 20" x 4.5" sediment filter. This is an economical solution to reduce fine sediment, including rust, sand, and scale particulates. It has a high dirt-catching capacity and flow rates due to its string-wound construction. It is suitable for use in a wide range of sediment applications including drinking water purification, irrigation, and industrial processes.