Nominal 20 Micron Pleated Cellulose Sediment Water Filter Cartridge Reduces sand, sediment, silt, rust particles, and scale particles. Has pleated walls for dirt-holding capacity. Recommended for chlorinated water supplies. *NOT recommended for wells. Pleated around a polypropylene core for added strength and the ends are immersed in a thermo-setting vinyl plastisol. Has an external netted sheath that helps retain uniform pleat spacing in high flow and pulsating flow streams. The overlap seam is sonically welded to reduce bypass, improving filtration efficiency.