Pentair Pentek R Series cartridges are made from a durable, non-woven polyester fabric pleated around a polypropylene core for added strength. The R30-20 reduces dirt, sand, silt, rust, and scale at a nominal 30 micron rating, helping keep your water cleaner while helping protect appliances, plumbing, and downstream filters. This 20-inch cartridge offers a large pleated polyester surface area to maximize dirt-holding capacity and extend the time between changes. A sonically welded overlap seam reduces internal bypass to improve filtration efficiency, and the chemical-resistant media can be rinsed and reused to extend cartridge life. Initial pressure drop is less than 1 psi at 10 gpm. This 20" x 2.5" cartridge is a drop-in replacement for standard 20-inch housings and works with both municipal (chlorinated) and well (non-chlorinated) water. It operates across a temperature range of 40 to 125 degrees F. Replace the cartridge when you notice a drop in water pressure or water quality.