The Pentair Pentek R50 is a 50 micron pleated sediment cartridge made from durable, non-woven polyester fabric pleated around a polypropylene core for added strength. The pleated design reduces dirt, sand, silt, rust, and scale, helping keep your water cleaner while helping protect appliances, plumbing, and downstream filters. Because the polyester media works with both chlorinated and non-chlorinated water, it is well suited to well water as well as municipal supplies. The overlap seam is sonically welded to reduce internal bypass and improve filtration efficiency. The standard 9.75-inch cartridge holds more than four square feet of polyester fabric, and the pleated, reusable construction can be cleaned and reused to extend the time between changes. With maximum dimensions of 2.63" x 9.75", this cartridge fits standard 10" x 2.5" housings and has an initial pressure drop of less than 1 psi at 10 gpm over a 40 to 125 degrees F temperature range. Clean or replace the cartridge when you notice a drop in water pressure or water quality.