Harmsco PP-S-1 9 3/4 1 Micron Absolute Poly-Pleat Filter Cartridge Pleated polypropylene design has a greater surface area than standard filters and increased particle removal 1 micron absolute rating filter media removes cysts and other impurities for safer drinking water End caps, center tube, and media are thermally bonded to ensure superior filter strength and sealing Economically priced filters meet FDA requirements for use in potable water