Pentek WP.5BB97P String-Wound Polypropylene Filter Cartridge, 10" x 4.5", 0.5 Micron Reduces sand, silt, scale, and rust particles in residential and municipal drinking water and industrial fluid applications Nominal filtration rating of 0.5 micron Polypropylene cord precisely wound on a rigid polypropylene core for high dirt-loading capacity Initial pressure drop of 5 psi at a flow rate of 10 gpm Temperature range of 40 to 165 degrees F (4.4 to 74 degrees C)