The Pentair Pentek R50-BB is a 50-micron pleated polyester sediment filter cartridge designed for standard 10" x 4.5" Big Blue whole house filter housings. Each cartridge features more than 16 square feet of durable, non-woven polyester fabric pleated around a polypropylene core, providing significantly greater dirt-holding capacity than non-pleated alternatives. The media effectively captures dirt, sand, silt, rust, and other particulates and helps protect plumbing fixtures, water-using appliances, and downstream filtration stages. The overlap seam on each cartridge is sonically welded to minimize internal bypass, improving overall filtration efficiency. Molded polypropylene endcaps with integrated gaskets provide a secure, leak-free fit. The initial pressure drop is less than 1 psi at 10 gpm, helping maintain consistent water pressure throughout the system. Operating temperature range is 40 to 125 degrees F. The polyester media is washable and reusable, allowing cartridges to be cleaned and reinstalled to extend service life. This 2-pack fits any standard Big Blue 10" x 4.5" housing and is suitable for residential, commercial, and light industrial sediment pre-filtration applications.