The Intelifil Water Softener Cartridges, utilizing a dark cation bead resin are designed to remove dissolved mineral hardness such as calcium and magnesium. These hardness minerals are typically the primary cause of scaling in pipes and water using appliances. Use a compensated hardness calculation that accounts for all mineral hardness of the influent supply to more accurately determine the gallon capacity of these cartridges.10 Micron Nominal RatingFits Most 10" Big Blue HousingsTemperature Range: 40 F to 100 FPressure Range: 25 PSI to 100 PSI