Pentair Pentek P Series sediment cartridges are manufactured from pure 100% polypropylene fibers, carefully spun together to form a true gradient density from the outer to the inner surfaces. The P5-20 carries a nominal 5 micron rating and reduces dirt, sand, silt, scale, and rust particles to keep your water cleaner and help protect appliances, plumbing, and downstream filters. The P5-20 is tested and certified by NSF International to NSF/ANSI Standard 42 for material requirements. Designed for purity, the polypropylene media offers superior chemical resistance and will not impart taste, odor, or color to the filtered water when used within its temperature limit. The coreless strength of the cartridge comes from sintering the many fibers into a single solid matrix. This 20-inch cartridge measures 20" x 2.5" and drops into standard 20-inch housings for whole-house, residential, commercial, and light industrial use on both chlorinated and non-chlorinated water. Initial pressure drop is just 0.6 psi at 10 gpm over a 40 to 145 degrees F operating range. Replace the cartridge whenever you notice a drop in water pressure or water quality.