Water Filter Replacement Cartridges for home, whole house, commercial and industrial applications. We carry a number of "filter inserts" that are known in the industry as "cartridges". Filter Cartridges below are separated by size and application. Products are listed in the following order: 10"x2.5" filters, shower replacement cartridges, 20"x2.5" filters, 10"x2.5" (10x4.5) filters, 20"x2.5" (20x4.5) (30x2.5'') 40x2.5''filters, inline and other sizes. Please browse our catalog or use Search function if you know model number.