Cartridge Water Filters - SD Series 2 Piece Filter Kits. G.F. Water Filtration. 5" 205SD 10" 210SD, CFA disposable spiral wound cartridge, Polyphosphate salts cartridge and Activated carbons cartridge filter kits. Reinforced polypropylene head. Thermoplastic transparent bowl. 3/4"BSPF ports - brass insert.