Fortress Filtration Big Blue 20" x 4.5" Water Filter Housing/Whole House 3/4" 1 inch/wrench/bracket Fortress Filtration Premium Water Filter Housing Big Blue style holds 20" x 4.5" standard filters. Use with carbon or sediment filter cartridges. Designed to work with either 3/4" or 1" plumbing supply lines. Includes filter wrench, Mounting bracket, plumbing adapters and pressure release.