Replacement water filter housings available in all sizes - 5" - 10" - 20" Standard 2.5" or 4.5" Big Blue or Big White. Will suit all standard water filter cartridge sizes 5" x 2.5" Inch - 10" x 2.5" Inch - 10" x 4.5" Inch - 20" x 2.5" Inch & 20" x 4.5" Inch. We stock a full range of Stainless steel housings in 304 and 316 grade.