Pentek Filter Cartridge: Radial Flow Carbon RFC20 2.5 in. x 20 in. Provides effective chlorine taste odor reduction. Unique design reduces carbon fines in filtered water. RFC Series cartridges are constructed with 70-micron porous polythylene outer shell and durable polypropylene end caps. The 2-3/4 OD cartridges have a polypropylene core and cartridges incorporate a spun polypropylene core. Sandwiched between the outer shell and the core is a bed of granular activated carbon (GAC). The unique radial flow design offers the benefits of granular activated carbon (GAC) filtration, such as low pressure drop, while at the same time significantly reducing the release of carbon fines commonly associated with GAC style cartridges. RFC Series cartridges are available in a wide variety of sizes and are ideal point-of-entry (POE) and other high flow rate applications. Based on manufacturer's internal testing. Initial Flow Rate: 0.90 psi at 2 gpm. Chlorine Taste Odor Reduction at Flow Rate 35,000 gallons at 2 gpm