About This CARTRIDGES USE a sodium based, non-solvent rinsed softening resin to reduce hardness, minerals and scale deposits in low flow rate applications FITS ALL 20" Big Blue or other heavy duty housings and can replace any 20" x 4.5" water softener cartridge CARTRIDGE STYLE DESIGN PROVIDES A CONVENIENT SOLUTION for delivering softened water to protect sensitive water delivery equipment DESIGNED TO ALLOW OPTIMAL CONTACT between water and resin surfaces, ensuring maximum ion exchange 4,500 GRAIN CAPACITY. Cartridge utilizes single-use resin technologies for maximum life grains capacity Overview Material : Cation Resin Product Dimensions : 4.5"D x 4.5"W x 20"H Item Weight : 9.7 Pounds External Testing Certification : FDA Product Benefits : Reduces hardness, minerals, and scale deposits in low flow rate applications; Protects sensitive water delivery equipment; Provides superior protection for medical equipment, coffee and espresso appliances, beverage and food service machines Reduces hardness, minerals, and scale deposits in low flow rate applications; Protects sensitive water delivery equipment; Provides superior protection for medical equipment, coffee and espresso app… See more